From patchwork Fri Apr 10 15:48:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11483379 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9D2B7912 for ; Fri, 10 Apr 2020 16:00:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D0D120CC7 for ; Fri, 10 Apr 2020 16:00:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726793AbgDJQA5 (ORCPT ); Fri, 10 Apr 2020 12:00:57 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:55398 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726712AbgDJQAw (ORCPT ); Fri, 10 Apr 2020 12:00:52 -0400 Received: from 185.80.35.16 (185.80.35.16) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.415) id 3cc4c344a33009c7; Fri, 10 Apr 2020 18:00:49 +0200 From: "Rafael J. Wysocki" To: Linux PM , Alan Stern Cc: Linux ACPI , Linux PCI , LKML , Bjorn Helgaas , Greg Kroah-Hartman , Mika Westerberg , Hans De Goede , Ulf Hansson Subject: [PATCH 1/7] PM: sleep: core: Simplify the SMART_SUSPEND flag handling Date: Fri, 10 Apr 2020 17:48:01 +0200 Message-ID: <2654948.CWnpW94V0n@kreacher> In-Reply-To: <1888197.j9z7NJ8yPn@kreacher> References: <1888197.j9z7NJ8yPn@kreacher> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: "Rafael J. Wysocki" The code to handle the SMART_SUSPEND driver PM flag is hard to follow and somewhat inconsistent with respect to devices without middle-layer (subsystem) callbacks. Namely, for those devices the core takes the role of a middle layer in providing the expected ordering of execution of callbacks (under the assumption that the drivers setting SMART_SUSPEND can reuse their PM-runtime callbacks directly for system-wide suspend). To that end, it prevents driver ->suspend_late and ->suspend_noirq callbacks from being executed for devices that are still runtime-suspended in __device_suspend_late(), because running the same callback funtion that was previously run by PM-runtime for them may be invalid. However, it does that only for devices without any middle-layer callbacks for the late/noirq/early suspend/resume phases even though it would be simpler and more consistent to skip the driver-lavel callbacks for all devices with SMART_SUSPEND set that are runtime-suspended in __device_suspend_late(). Simplify the code in accordance with the above observation. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 118 +++++++++++++++------------------------------- 1 file changed, 39 insertions(+), 79 deletions(-) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index fdd508a78ffd..5d0225573bbe 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -561,24 +561,6 @@ static void dpm_watchdog_clear(struct dpm_watchdog *wd) /*------------------------- Resume routines -------------------------*/ -/** - * suspend_event - Return a "suspend" message for given "resume" one. - * @resume_msg: PM message representing a system-wide resume transition. - */ -static pm_message_t suspend_event(pm_message_t resume_msg) -{ - switch (resume_msg.event) { - case PM_EVENT_RESUME: - return PMSG_SUSPEND; - case PM_EVENT_THAW: - case PM_EVENT_RESTORE: - return PMSG_FREEZE; - case PM_EVENT_RECOVER: - return PMSG_HIBERNATE; - } - return PMSG_ON; -} - /** * dev_pm_may_skip_resume - System-wide device resume optimization check. * @dev: Target device. @@ -656,37 +638,36 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn if (!dpm_wait_for_superior(dev, async)) goto Out; - skip_resume = dev_pm_may_skip_resume(dev); - callback = dpm_subsys_resume_noirq_cb(dev, state, &info); - if (callback) + if (callback) { + skip_resume = false; goto Run; + } + skip_resume = dev_pm_may_skip_resume(dev); if (skip_resume) goto Skip; - if (dev_pm_smart_suspend_and_suspended(dev)) { - pm_message_t suspend_msg = suspend_event(state); - - /* - * If "freeze" callbacks have been skipped during a transition - * related to hibernation, the subsequent "thaw" callbacks must - * be skipped too or bad things may happen. Otherwise, resume - * callbacks are going to be run for the device, so its runtime - * PM status must be changed to reflect the new state after the - * transition under way. - */ - if (!dpm_subsys_suspend_late_cb(dev, suspend_msg, NULL) && - !dpm_subsys_suspend_noirq_cb(dev, suspend_msg, NULL)) { - if (state.event == PM_EVENT_THAW) { - skip_resume = true; - goto Skip; - } else { - pm_runtime_set_active(dev); - } - } + /* + * If "freeze" driver callbacks have been skipped during hibernation, + * because the device was runtime-suspended in __device_suspend_late(), + * the corresponding "thaw" callbacks must be skipped too, because + * running them for a runtime-suspended device may not be valid. + */ + if (dev_pm_smart_suspend_and_suspended(dev) && + state.event == PM_EVENT_THAW) { + skip_resume = true; + goto Skip; } + /* + * The device is going to be resumed, so set its PM-runtime status to + * "active", but do that only if DPM_FLAG_SMART_SUSPEND is set to avoid + * confusing drivers that don't use it. + */ + if (dev_pm_smart_suspend_and_suspended(dev)) + pm_runtime_set_active(dev); + if (dev->driver && dev->driver->pm) { info = "noirq driver "; callback = pm_noirq_op(dev->driver->pm, state); @@ -1274,32 +1255,6 @@ static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev, return callback; } -static bool device_must_resume(struct device *dev, pm_message_t state, - bool no_subsys_suspend_noirq) -{ - pm_message_t resume_msg = resume_event(state); - - /* - * If all of the device driver's "noirq", "late" and "early" callbacks - * are invoked directly by the core, the decision to allow the device to - * stay in suspend can be based on its current runtime PM status and its - * wakeup settings. - */ - if (no_subsys_suspend_noirq && - !dpm_subsys_suspend_late_cb(dev, state, NULL) && - !dpm_subsys_resume_early_cb(dev, resume_msg, NULL) && - !dpm_subsys_resume_noirq_cb(dev, resume_msg, NULL)) - return !pm_runtime_status_suspended(dev) && - (resume_msg.event != PM_EVENT_RESUME || - (device_can_wakeup(dev) && !device_may_wakeup(dev))); - - /* - * The only safe strategy here is to require that if the device may not - * be left in suspend, resume callbacks must be invoked for it. - */ - return !dev->power.may_skip_resume; -} - /** * __device_suspend_noirq - Execute a "noirq suspend" callback for given device. * @dev: Device to handle. @@ -1313,7 +1268,6 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a { pm_callback_t callback; const char *info; - bool no_subsys_cb = false; int error = 0; TRACE_DEVICE(dev); @@ -1331,9 +1285,7 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a if (callback) goto Run; - no_subsys_cb = !dpm_subsys_suspend_late_cb(dev, state, NULL); - - if (dev_pm_smart_suspend_and_suspended(dev) && no_subsys_cb) + if (dev_pm_smart_suspend_and_suspended(dev)) goto Skip; if (dev->driver && dev->driver->pm) { @@ -1351,13 +1303,16 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a Skip: dev->power.is_noirq_suspended = true; - if (dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED)) { - dev->power.must_resume = dev->power.must_resume || - atomic_read(&dev->power.usage_count) > 1 || - device_must_resume(dev, state, no_subsys_cb); - } else { + /* + * Skipping the resume of devices that were in use right before the + * system suspend (as indicated by their PM-runtime usage counters) + * would be suboptimal. Also resume them if doing that is not allowed + * to be skipped. + */ + if (atomic_read(&dev->power.usage_count) > 1 || + !(dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED) && + dev->power.may_skip_resume)) dev->power.must_resume = true; - } if (dev->power.must_resume) dpm_superior_set_must_resume(dev); @@ -1539,9 +1494,14 @@ static int __device_suspend_late(struct device *dev, pm_message_t state, bool as if (callback) goto Run; - if (dev_pm_smart_suspend_and_suspended(dev) && - !dpm_subsys_suspend_noirq_cb(dev, state, NULL)) + if (dev_pm_smart_suspend_and_suspended(dev)) { + /* + * In principle, the resume of the device may be skippend if it + * remains in runtime suspend at this point. + */ + dev->power.may_skip_resume = true; goto Skip; + } if (dev->driver && dev->driver->pm) { info = "late driver "; From patchwork Fri Apr 10 15:48:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11483385 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2A6EF912 for ; Fri, 10 Apr 2020 16:01:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 04DDE2137B for ; Fri, 10 Apr 2020 16:01:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726765AbgDJQAw (ORCPT ); Fri, 10 Apr 2020 12:00:52 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:58474 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726681AbgDJQAv (ORCPT ); Fri, 10 Apr 2020 12:00:51 -0400 Received: from 185.80.35.16 (185.80.35.16) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.415) id ebbf3e2dfb3ed491; Fri, 10 Apr 2020 18:00:48 +0200 From: "Rafael J. Wysocki" To: Linux PM , Alan Stern Cc: Linux ACPI , Linux PCI , LKML , Bjorn Helgaas , Greg Kroah-Hartman , Mika Westerberg , Hans De Goede , Ulf Hansson Subject: [PATCH 2/7] PM: sleep: core: Fold functions into their callers Date: Fri, 10 Apr 2020 17:48:45 +0200 Message-ID: <3637853.KA6EFo2J0E@kreacher> In-Reply-To: <1888197.j9z7NJ8yPn@kreacher> References: <1888197.j9z7NJ8yPn@kreacher> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: "Rafael J. Wysocki" Fold four functions in the PM core that each have only one caller now into their callers. No intentional functional impact. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 198 ++++++++++++++-------------------------------- 1 file changed, 60 insertions(+), 138 deletions(-) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 5d0225573bbe..75d7cdb4de9c 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -573,43 +573,6 @@ bool dev_pm_may_skip_resume(struct device *dev) return !dev->power.must_resume && pm_transition.event != PM_EVENT_RESTORE; } -static pm_callback_t dpm_subsys_resume_noirq_cb(struct device *dev, - pm_message_t state, - const char **info_p) -{ - pm_callback_t callback; - const char *info; - - if (dev->pm_domain) { - info = "noirq power domain "; - callback = pm_noirq_op(&dev->pm_domain->ops, state); - } else if (dev->type && dev->type->pm) { - info = "noirq type "; - callback = pm_noirq_op(dev->type->pm, state); - } else if (dev->class && dev->class->pm) { - info = "noirq class "; - callback = pm_noirq_op(dev->class->pm, state); - } else if (dev->bus && dev->bus->pm) { - info = "noirq bus "; - callback = pm_noirq_op(dev->bus->pm, state); - } else { - return NULL; - } - - if (info_p) - *info_p = info; - - return callback; -} - -static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev, - pm_message_t state, - const char **info_p); - -static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev, - pm_message_t state, - const char **info_p); - /** * device_resume_noirq - Execute a "noirq resume" callback for given device. * @dev: Device to handle. @@ -621,8 +584,8 @@ static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev, */ static int device_resume_noirq(struct device *dev, pm_message_t state, bool async) { - pm_callback_t callback; - const char *info; + pm_callback_t callback = NULL; + const char *info = NULL; bool skip_resume; int error = 0; @@ -638,7 +601,19 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn if (!dpm_wait_for_superior(dev, async)) goto Out; - callback = dpm_subsys_resume_noirq_cb(dev, state, &info); + if (dev->pm_domain) { + info = "noirq power domain "; + callback = pm_noirq_op(&dev->pm_domain->ops, state); + } else if (dev->type && dev->type->pm) { + info = "noirq type "; + callback = pm_noirq_op(dev->type->pm, state); + } else if (dev->class && dev->class->pm) { + info = "noirq class "; + callback = pm_noirq_op(dev->class->pm, state); + } else if (dev->bus && dev->bus->pm) { + info = "noirq bus "; + callback = pm_noirq_op(dev->bus->pm, state); + } if (callback) { skip_resume = false; goto Run; @@ -791,35 +766,6 @@ void dpm_resume_noirq(pm_message_t state) cpuidle_resume(); } -static pm_callback_t dpm_subsys_resume_early_cb(struct device *dev, - pm_message_t state, - const char **info_p) -{ - pm_callback_t callback; - const char *info; - - if (dev->pm_domain) { - info = "early power domain "; - callback = pm_late_early_op(&dev->pm_domain->ops, state); - } else if (dev->type && dev->type->pm) { - info = "early type "; - callback = pm_late_early_op(dev->type->pm, state); - } else if (dev->class && dev->class->pm) { - info = "early class "; - callback = pm_late_early_op(dev->class->pm, state); - } else if (dev->bus && dev->bus->pm) { - info = "early bus "; - callback = pm_late_early_op(dev->bus->pm, state); - } else { - return NULL; - } - - if (info_p) - *info_p = info; - - return callback; -} - /** * device_resume_early - Execute an "early resume" callback for given device. * @dev: Device to handle. @@ -830,8 +776,8 @@ static pm_callback_t dpm_subsys_resume_early_cb(struct device *dev, */ static int device_resume_early(struct device *dev, pm_message_t state, bool async) { - pm_callback_t callback; - const char *info; + pm_callback_t callback = NULL; + const char *info = NULL; int error = 0; TRACE_DEVICE(dev); @@ -846,9 +792,19 @@ static int device_resume_early(struct device *dev, pm_message_t state, bool asyn if (!dpm_wait_for_superior(dev, async)) goto Out; - callback = dpm_subsys_resume_early_cb(dev, state, &info); - - if (!callback && dev->driver && dev->driver->pm) { + if (dev->pm_domain) { + info = "early power domain "; + callback = pm_late_early_op(&dev->pm_domain->ops, state); + } else if (dev->type && dev->type->pm) { + info = "early type "; + callback = pm_late_early_op(dev->type->pm, state); + } else if (dev->class && dev->class->pm) { + info = "early class "; + callback = pm_late_early_op(dev->class->pm, state); + } else if (dev->bus && dev->bus->pm) { + info = "early bus "; + callback = pm_late_early_op(dev->bus->pm, state); + } else if (dev->driver && dev->driver->pm) { info = "early driver "; callback = pm_late_early_op(dev->driver->pm, state); } @@ -1226,35 +1182,6 @@ static void dpm_superior_set_must_resume(struct device *dev) device_links_read_unlock(idx); } -static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev, - pm_message_t state, - const char **info_p) -{ - pm_callback_t callback; - const char *info; - - if (dev->pm_domain) { - info = "noirq power domain "; - callback = pm_noirq_op(&dev->pm_domain->ops, state); - } else if (dev->type && dev->type->pm) { - info = "noirq type "; - callback = pm_noirq_op(dev->type->pm, state); - } else if (dev->class && dev->class->pm) { - info = "noirq class "; - callback = pm_noirq_op(dev->class->pm, state); - } else if (dev->bus && dev->bus->pm) { - info = "noirq bus "; - callback = pm_noirq_op(dev->bus->pm, state); - } else { - return NULL; - } - - if (info_p) - *info_p = info; - - return callback; -} - /** * __device_suspend_noirq - Execute a "noirq suspend" callback for given device. * @dev: Device to handle. @@ -1266,8 +1193,8 @@ static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev, */ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async) { - pm_callback_t callback; - const char *info; + pm_callback_t callback = NULL; + const char *info = NULL; int error = 0; TRACE_DEVICE(dev); @@ -1281,7 +1208,19 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a if (dev->power.syscore || dev->power.direct_complete) goto Complete; - callback = dpm_subsys_suspend_noirq_cb(dev, state, &info); + if (dev->pm_domain) { + info = "noirq power domain "; + callback = pm_noirq_op(&dev->pm_domain->ops, state); + } else if (dev->type && dev->type->pm) { + info = "noirq type "; + callback = pm_noirq_op(dev->type->pm, state); + } else if (dev->class && dev->class->pm) { + info = "noirq class "; + callback = pm_noirq_op(dev->class->pm, state); + } else if (dev->bus && dev->bus->pm) { + info = "noirq bus "; + callback = pm_noirq_op(dev->bus->pm, state); + } if (callback) goto Run; @@ -1429,35 +1368,6 @@ static void dpm_propagate_wakeup_to_parent(struct device *dev) spin_unlock_irq(&parent->power.lock); } -static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev, - pm_message_t state, - const char **info_p) -{ - pm_callback_t callback; - const char *info; - - if (dev->pm_domain) { - info = "late power domain "; - callback = pm_late_early_op(&dev->pm_domain->ops, state); - } else if (dev->type && dev->type->pm) { - info = "late type "; - callback = pm_late_early_op(dev->type->pm, state); - } else if (dev->class && dev->class->pm) { - info = "late class "; - callback = pm_late_early_op(dev->class->pm, state); - } else if (dev->bus && dev->bus->pm) { - info = "late bus "; - callback = pm_late_early_op(dev->bus->pm, state); - } else { - return NULL; - } - - if (info_p) - *info_p = info; - - return callback; -} - /** * __device_suspend_late - Execute a "late suspend" callback for given device. * @dev: Device to handle. @@ -1468,8 +1378,8 @@ static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev, */ static int __device_suspend_late(struct device *dev, pm_message_t state, bool async) { - pm_callback_t callback; - const char *info; + pm_callback_t callback = NULL; + const char *info = NULL; int error = 0; TRACE_DEVICE(dev); @@ -1490,7 +1400,19 @@ static int __device_suspend_late(struct device *dev, pm_message_t state, bool as if (dev->power.syscore || dev->power.direct_complete) goto Complete; - callback = dpm_subsys_suspend_late_cb(dev, state, &info); + if (dev->pm_domain) { + info = "late power domain "; + callback = pm_late_early_op(&dev->pm_domain->ops, state); + } else if (dev->type && dev->type->pm) { + info = "late type "; + callback = pm_late_early_op(dev->type->pm, state); + } else if (dev->class && dev->class->pm) { + info = "late class "; + callback = pm_late_early_op(dev->class->pm, state); + } else if (dev->bus && dev->bus->pm) { + info = "late bus "; + callback = pm_late_early_op(dev->bus->pm, state); + } if (callback) goto Run; From patchwork Fri Apr 10 15:51:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11483395 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7CA201744 for ; Fri, 10 Apr 2020 16:01:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5573F2137B for ; Fri, 10 Apr 2020 16:01:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726736AbgDJQAu (ORCPT ); Fri, 10 Apr 2020 12:00:50 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:65357 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726680AbgDJQAu (ORCPT ); Fri, 10 Apr 2020 12:00:50 -0400 Received: from 185.80.35.16 (185.80.35.16) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.415) id 6e531731d97e64ed; Fri, 10 Apr 2020 18:00:47 +0200 From: "Rafael J. Wysocki" To: Linux PM , Alan Stern Cc: Linux ACPI , Linux PCI , LKML , Bjorn Helgaas , Greg Kroah-Hartman , Mika Westerberg , Hans De Goede , Ulf Hansson , Linux PCI , Linux ACPI , Bjorn Helgaas Subject: [PATCH 3/7] PM: sleep: core: Do not skip callbacks in the resume phase Date: Fri, 10 Apr 2020 17:51:23 +0200 Message-ID: <2319877.g3gYOn6k3l@kreacher> In-Reply-To: <1888197.j9z7NJ8yPn@kreacher> References: <1888197.j9z7NJ8yPn@kreacher> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: "Rafael J. Wysocki" The current code in device_resume_noirq() causes the entire early resume and resume phases of device suspend to be skipped for devices for which the noirq resume phase have been skipped (due to the LEAVE_SUSPENDED flag being set) on the premise that those devices should stay in runtime-suspend after system-wide resume. However, that may not be correct in two situations. First, the middle layer (subsystem) noirq resume callback may be missing for a given device, but its early resume callback may be present and it may need to do something even if it decides to skip the driver callback. Second, if the device's wakeup settings were adjusted in the suspend phase without resuming the device (that was in runtime suspend at that time), they most likely need to be adjusted again in the resume phase and so the driver callback in that phase needs to be run. For the above reason, modify the core to allow the middle layer ->resume_late callback to run even if its ->resume_noirq callback is missing (and the core has skipped the driver-level callback in that phase) and to allow all device callbacks to run in the resume phase. Also make the core set the PM-runtime status of devices with SMART_SUSPEND set whose resume callbacks are not skipped to "active" in the "noirq" resume phase and update the affected subsystems (PCI and ACPI) accordingly. After this change, middle-layer (subsystem) callbacks will always be invoked in all phases of system suspend and resume and driver callbacks will always run in the prepare, suspend, resume, and complete phases for all devices. For devices with SMART_SUSPEND set, driver callbacks will be skipped in the late and noirq phases of system suspend if those devices remain in runtime suspend in __device_suspend_late(). Driver callbacks will also be skipped for them during the noirq and early phases of the "thaw" transition related to hibernation. For devices with LEAVE_SUSPENDED set, driver callbacks will be skipped in the noirq and early phases of system resume if (1) the corresponding callbacks were skipped for them during system suspend or (2) if the middle layer (subsystem) allows the resume driver callbacks to be skipped by setting the power.may_skip_resume flag for the device during system suspend. For all devices with SMART_SUSPEND set whose driver callbacks are invoked during system resume, the PM-runtime status will be set to "active" (by the core). Signed-off-by: Rafael J. Wysocki --- Documentation/power/pci.rst | 5 +-- drivers/acpi/acpi_lpss.c | 6 ++-- drivers/acpi/device_pm.c | 15 ++++---- drivers/base/power/main.c | 84 ++++++++++++++++++++++----------------------- drivers/pci/pci-driver.c | 18 +++++----- 5 files changed, 61 insertions(+), 67 deletions(-) diff --git a/Documentation/power/pci.rst b/Documentation/power/pci.rst index 0924d29636ad..a39b2461919a 100644 --- a/Documentation/power/pci.rst +++ b/Documentation/power/pci.rst @@ -1035,10 +1035,7 @@ This flag is checked by the PM core, but the PCI bus type informs the PM core which devices may be left in suspend from its perspective (that happens during the "noirq" phase of system-wide suspend and analogous transitions) and next it uses the dev_pm_may_skip_resume() helper to decide whether or not to return from -pci_pm_resume_noirq() early, as the PM core will skip the remaining resume -callbacks for the device during the transition under way and will set its -runtime PM status to "suspended" if dev_pm_may_skip_resume() returns "true" for -it. +pci_pm_resume_noirq() and pci_pm_resume_early() upfront. 3.2. Device Runtime Power Management ------------------------------------ diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index dee999938213..c4a84df6cc98 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -1093,6 +1093,9 @@ static int acpi_lpss_resume_early(struct device *dev) if (pdata->dev_desc->resume_from_noirq) return 0; + if (dev_pm_may_skip_resume(dev)) + return 0; + return acpi_lpss_do_resume_early(dev); } @@ -1105,9 +1108,6 @@ static int acpi_lpss_resume_noirq(struct device *dev) if (dev_pm_may_skip_resume(dev)) return 0; - if (dev_pm_smart_suspend_and_suspended(dev)) - pm_runtime_set_active(dev); - ret = pm_generic_resume_noirq(dev); if (ret) return ret; diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index b2263ec67b43..399684085f85 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -1132,14 +1132,6 @@ static int acpi_subsys_resume_noirq(struct device *dev) if (dev_pm_may_skip_resume(dev)) return 0; - /* - * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend - * during system suspend, so update their runtime PM status to "active" - * as they will be put into D0 going forward. - */ - if (dev_pm_smart_suspend_and_suspended(dev)) - pm_runtime_set_active(dev); - return pm_generic_resume_noirq(dev); } @@ -1153,7 +1145,12 @@ static int acpi_subsys_resume_noirq(struct device *dev) */ static int acpi_subsys_resume_early(struct device *dev) { - int ret = acpi_dev_resume(dev); + int ret; + + if (dev_pm_may_skip_resume(dev)) + return 0; + + ret = acpi_dev_resume(dev); return ret ? ret : pm_generic_resume_early(dev); } diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 75d7cdb4de9c..66f205d7c7a3 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -565,12 +565,21 @@ static void dpm_watchdog_clear(struct dpm_watchdog *wd) * dev_pm_may_skip_resume - System-wide device resume optimization check. * @dev: Target device. * - * Checks whether or not the device may be left in suspend after a system-wide - * transition to the working state. + * Driver-level resume callbacks can be skipped for @dev if its configuration is + * suitable for that (power.must_resume is not set) and the current transition + * is not the hibernation-related "restore" one (in which case all devices must + * be resumed) or the current transition is the hibernation-related "thaw" one + * and the driver-level callbacks were skipped for @dev during the corresponding + * "freeze" transition (which happens when DPM_FLAG_SMART_SUSPEND is set and the + * device remains in runtime suspend), so running the "thaw" callbacks for it + * may be invalid. */ bool dev_pm_may_skip_resume(struct device *dev) { - return !dev->power.must_resume && pm_transition.event != PM_EVENT_RESTORE; + return (!dev->power.must_resume && + pm_transition.event != PM_EVENT_RESTORE) || + (dev_pm_smart_suspend_and_suspended(dev) && + pm_transition.event == PM_EVENT_THAW); } /** @@ -601,6 +610,22 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn if (!dpm_wait_for_superior(dev, async)) goto Out; + skip_resume = dev_pm_may_skip_resume(dev); + /* + * If the driver callback is skipped below or by the middle layer + * callback and device_resume_early() also skips the driver callback for + * this device later, it needs to appear as "suspended" to PM-runtime, + * so change its status accordingly. + * + * Otherwise, the device is going to be resumed, so set its PM-runtime + * status to "active", but do that only if DPM_FLAG_SMART_SUSPEND is set + * to avoid confusing drivers that don't use it. + */ + if (skip_resume) + pm_runtime_set_suspended(dev); + else if (dev_pm_smart_suspend_and_suspended(dev)) + pm_runtime_set_active(dev); + if (dev->pm_domain) { info = "noirq power domain "; callback = pm_noirq_op(&dev->pm_domain->ops, state); @@ -614,35 +639,12 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn info = "noirq bus "; callback = pm_noirq_op(dev->bus->pm, state); } - if (callback) { - skip_resume = false; + if (callback) goto Run; - } - skip_resume = dev_pm_may_skip_resume(dev); if (skip_resume) goto Skip; - /* - * If "freeze" driver callbacks have been skipped during hibernation, - * because the device was runtime-suspended in __device_suspend_late(), - * the corresponding "thaw" callbacks must be skipped too, because - * running them for a runtime-suspended device may not be valid. - */ - if (dev_pm_smart_suspend_and_suspended(dev) && - state.event == PM_EVENT_THAW) { - skip_resume = true; - goto Skip; - } - - /* - * The device is going to be resumed, so set its PM-runtime status to - * "active", but do that only if DPM_FLAG_SMART_SUSPEND is set to avoid - * confusing drivers that don't use it. - */ - if (dev_pm_smart_suspend_and_suspended(dev)) - pm_runtime_set_active(dev); - if (dev->driver && dev->driver->pm) { info = "noirq driver "; callback = pm_noirq_op(dev->driver->pm, state); @@ -654,20 +656,6 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn Skip: dev->power.is_noirq_suspended = false; - if (skip_resume) { - /* Make the next phases of resume skip the device. */ - dev->power.is_late_suspended = false; - dev->power.is_suspended = false; - /* - * The device is going to be left in suspend, but it might not - * have been in runtime suspend before the system suspended, so - * its runtime PM status needs to be updated to avoid confusing - * the runtime PM framework when runtime PM is enabled for the - * device again. - */ - pm_runtime_set_suspended(dev); - } - Out: complete_all(&dev->power.completion); TRACE_RESUME(error); @@ -804,15 +792,25 @@ static int device_resume_early(struct device *dev, pm_message_t state, bool asyn } else if (dev->bus && dev->bus->pm) { info = "early bus "; callback = pm_late_early_op(dev->bus->pm, state); - } else if (dev->driver && dev->driver->pm) { + } + if (callback) + goto Run; + + if (dev_pm_may_skip_resume(dev)) + goto Skip; + + if (dev->driver && dev->driver->pm) { info = "early driver "; callback = pm_late_early_op(dev->driver->pm, state); } +Run: error = dpm_run_callback(callback, dev, state, info); + +Skip: dev->power.is_late_suspended = false; - Out: +Out: TRACE_RESUME(error); pm_runtime_enable(dev); diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 0454ca0e4e3f..685fbf044911 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -896,14 +896,6 @@ static int pci_pm_resume_noirq(struct device *dev) if (dev_pm_may_skip_resume(dev)) return 0; - /* - * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend - * during system suspend, so update their runtime PM status to "active" - * as they are going to be put into D0 shortly. - */ - if (dev_pm_smart_suspend_and_suspended(dev)) - pm_runtime_set_active(dev); - /* * In the suspend-to-idle case, devices left in D0 during suspend will * stay in D0, so it is not necessary to restore or update their @@ -928,6 +920,14 @@ static int pci_pm_resume_noirq(struct device *dev) return 0; } +static int pci_pm_resume_early(struct device *dev) +{ + if (dev_pm_may_skip_resume(dev)) + return 0; + + return pm_generic_resume_early(dev); +} + static int pci_pm_resume(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); @@ -961,6 +961,7 @@ static int pci_pm_resume(struct device *dev) #define pci_pm_suspend_late NULL #define pci_pm_suspend_noirq NULL #define pci_pm_resume NULL +#define pci_pm_resume_early NULL #define pci_pm_resume_noirq NULL #endif /* !CONFIG_SUSPEND */ @@ -1358,6 +1359,7 @@ static const struct dev_pm_ops pci_dev_pm_ops = { .suspend = pci_pm_suspend, .suspend_late = pci_pm_suspend_late, .resume = pci_pm_resume, + .resume_early = pci_pm_resume_early, .freeze = pci_pm_freeze, .thaw = pci_pm_thaw, .poweroff = pci_pm_poweroff, From patchwork Fri Apr 10 15:51:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11483403 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A758E912 for ; Fri, 10 Apr 2020 16:01:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88C42214D8 for ; Fri, 10 Apr 2020 16:01:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726651AbgDJQBJ (ORCPT ); Fri, 10 Apr 2020 12:01:09 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:61041 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726678AbgDJQAt (ORCPT ); Fri, 10 Apr 2020 12:00:49 -0400 Received: from 185.80.35.16 (185.80.35.16) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.415) id a6c6ebd28b772ae9; Fri, 10 Apr 2020 18:00:47 +0200 From: "Rafael J. Wysocki" To: Linux PM , Alan Stern Cc: Linux ACPI , Linux PCI , LKML , Bjorn Helgaas , Greg Kroah-Hartman , Mika Westerberg , Hans De Goede , Ulf Hansson , Linux ACPI , Linux PCI , Bjorn Helgaas Subject: [PATCH 4/7] PM: sleep: core: Rename dev_pm_may_skip_resume() Date: Fri, 10 Apr 2020 17:51:35 +0200 Message-ID: <3171765.oZItDzeFuC@kreacher> In-Reply-To: <1888197.j9z7NJ8yPn@kreacher> References: <1888197.j9z7NJ8yPn@kreacher> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: "Rafael J. Wysocki" The name of dev_pm_may_skip_resume() may be easily confused with the power.may_skip_resume flag which is not checked by that function, so rename the former as dev_pm_skip_resume(). No functional impact. Signed-off-by: Rafael J. Wysocki --- Documentation/power/pci.rst | 2 +- drivers/acpi/acpi_lpss.c | 4 ++-- drivers/acpi/device_pm.c | 4 ++-- drivers/base/power/main.c | 8 ++++---- drivers/pci/pci-driver.c | 4 ++-- include/linux/pm.h | 2 +- 6 files changed, 12 insertions(+), 12 deletions(-) diff --git a/Documentation/power/pci.rst b/Documentation/power/pci.rst index a39b2461919a..aa1c7fce6cd0 100644 --- a/Documentation/power/pci.rst +++ b/Documentation/power/pci.rst @@ -1034,7 +1034,7 @@ device to be left in suspend after system-wide transitions to the working state. This flag is checked by the PM core, but the PCI bus type informs the PM core which devices may be left in suspend from its perspective (that happens during the "noirq" phase of system-wide suspend and analogous transitions) and next it -uses the dev_pm_may_skip_resume() helper to decide whether or not to return from +uses the dev_pm_skip_resume() helper to decide whether or not to return from pci_pm_resume_noirq() and pci_pm_resume_early() upfront. 3.2. Device Runtime Power Management diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index c4a84df6cc98..7632df1a5be3 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -1093,7 +1093,7 @@ static int acpi_lpss_resume_early(struct device *dev) if (pdata->dev_desc->resume_from_noirq) return 0; - if (dev_pm_may_skip_resume(dev)) + if (dev_pm_skip_resume(dev)) return 0; return acpi_lpss_do_resume_early(dev); @@ -1105,7 +1105,7 @@ static int acpi_lpss_resume_noirq(struct device *dev) int ret; /* Follow acpi_subsys_resume_noirq(). */ - if (dev_pm_may_skip_resume(dev)) + if (dev_pm_skip_resume(dev)) return 0; ret = pm_generic_resume_noirq(dev); diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 399684085f85..b9a3ade17587 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -1129,7 +1129,7 @@ EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq); */ static int acpi_subsys_resume_noirq(struct device *dev) { - if (dev_pm_may_skip_resume(dev)) + if (dev_pm_skip_resume(dev)) return 0; return pm_generic_resume_noirq(dev); @@ -1147,7 +1147,7 @@ static int acpi_subsys_resume_early(struct device *dev) { int ret; - if (dev_pm_may_skip_resume(dev)) + if (dev_pm_skip_resume(dev)) return 0; ret = acpi_dev_resume(dev); diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 66f205d7c7a3..21187ee37b22 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -562,7 +562,7 @@ static void dpm_watchdog_clear(struct dpm_watchdog *wd) /*------------------------- Resume routines -------------------------*/ /** - * dev_pm_may_skip_resume - System-wide device resume optimization check. + * dev_pm_skip_resume - System-wide device resume optimization check. * @dev: Target device. * * Driver-level resume callbacks can be skipped for @dev if its configuration is @@ -574,7 +574,7 @@ static void dpm_watchdog_clear(struct dpm_watchdog *wd) * device remains in runtime suspend), so running the "thaw" callbacks for it * may be invalid. */ -bool dev_pm_may_skip_resume(struct device *dev) +bool dev_pm_skip_resume(struct device *dev) { return (!dev->power.must_resume && pm_transition.event != PM_EVENT_RESTORE) || @@ -610,7 +610,7 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn if (!dpm_wait_for_superior(dev, async)) goto Out; - skip_resume = dev_pm_may_skip_resume(dev); + skip_resume = dev_pm_skip_resume(dev); /* * If the driver callback is skipped below or by the middle layer * callback and device_resume_early() also skips the driver callback for @@ -796,7 +796,7 @@ static int device_resume_early(struct device *dev, pm_message_t state, bool asyn if (callback) goto Run; - if (dev_pm_may_skip_resume(dev)) + if (dev_pm_skip_resume(dev)) goto Skip; if (dev->driver && dev->driver->pm) { diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 685fbf044911..ff2fc93e7a3b 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -893,7 +893,7 @@ static int pci_pm_resume_noirq(struct device *dev) pci_power_t prev_state = pci_dev->current_state; bool skip_bus_pm = pci_dev->skip_bus_pm; - if (dev_pm_may_skip_resume(dev)) + if (dev_pm_skip_resume(dev)) return 0; /* @@ -922,7 +922,7 @@ static int pci_pm_resume_noirq(struct device *dev) static int pci_pm_resume_early(struct device *dev) { - if (dev_pm_may_skip_resume(dev)) + if (dev_pm_skip_resume(dev)) return 0; return pm_generic_resume_early(dev); diff --git a/include/linux/pm.h b/include/linux/pm.h index e057d1fa2469..d89b7099f241 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -758,7 +758,7 @@ extern int pm_generic_poweroff_late(struct device *dev); extern int pm_generic_poweroff(struct device *dev); extern void pm_generic_complete(struct device *dev); -extern bool dev_pm_may_skip_resume(struct device *dev); +extern bool dev_pm_skip_resume(struct device *dev); extern bool dev_pm_smart_suspend_and_suspended(struct device *dev); #else /* !CONFIG_PM_SLEEP */ From patchwork Fri Apr 10 15:56:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11483411 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B56D2174A for ; Fri, 10 Apr 2020 16:01:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A182E21556 for ; Fri, 10 Apr 2020 16:01:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726826AbgDJQBP (ORCPT ); Fri, 10 Apr 2020 12:01:15 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:42545 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726646AbgDJQAt (ORCPT ); Fri, 10 Apr 2020 12:00:49 -0400 Received: from 185.80.35.16 (185.80.35.16) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.415) id 3a80db90d5ade516; Fri, 10 Apr 2020 18:00:46 +0200 From: "Rafael J. Wysocki" To: Linux PM , Alan Stern Cc: Linux ACPI , Linux PCI , LKML , Bjorn Helgaas , Greg Kroah-Hartman , Mika Westerberg , Hans De Goede , Ulf Hansson , Linux PCI , Bjorn Helgaas , DRI-devel , Intel Graphics , intel-wired-lan@lists.osuosl.org Subject: [PATCH 5/7] PM: sleep: core: Rename DPM_FLAG_NEVER_SKIP Date: Fri, 10 Apr 2020 17:56:13 +0200 Message-ID: <5092680.jloV5Ae5OO@kreacher> In-Reply-To: <1888197.j9z7NJ8yPn@kreacher> References: <1888197.j9z7NJ8yPn@kreacher> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: "Rafael J. Wysocki" Rename DPM_FLAG_NEVER_SKIP to DPM_FLAG_NO_DIRECT_COMPLETE which matches its purpose more closely. No functional impact. Signed-off-by: Rafael J. Wysocki Acked-by: Bjorn Helgaas # for PCI parts Acked-by: Jeff Kirsher --- Documentation/driver-api/pm/devices.rst | 6 +++--- Documentation/power/pci.rst | 10 +++++----- drivers/base/power/main.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 2 +- drivers/gpu/drm/i915/intel_runtime_pm.c | 2 +- drivers/gpu/drm/radeon/radeon_kms.c | 2 +- drivers/misc/mei/pci-me.c | 2 +- drivers/misc/mei/pci-txe.c | 2 +- drivers/net/ethernet/intel/e1000e/netdev.c | 2 +- drivers/net/ethernet/intel/igb/igb_main.c | 2 +- drivers/net/ethernet/intel/igc/igc_main.c | 2 +- drivers/pci/pcie/portdrv_pci.c | 2 +- include/linux/pm.h | 6 +++--- 13 files changed, 21 insertions(+), 21 deletions(-) diff --git a/Documentation/driver-api/pm/devices.rst b/Documentation/driver-api/pm/devices.rst index f66c7b9126ea..4ace0eba4506 100644 --- a/Documentation/driver-api/pm/devices.rst +++ b/Documentation/driver-api/pm/devices.rst @@ -361,9 +361,9 @@ the phases are: ``prepare``, ``suspend``, ``suspend_late``, ``suspend_noirq``. runtime PM disabled. This feature also can be controlled by device drivers by using the - ``DPM_FLAG_NEVER_SKIP`` and ``DPM_FLAG_SMART_PREPARE`` driver power - management flags. [Typically, they are set at the time the driver is - probed against the device in question by passing them to the + ``DPM_FLAG_NO_DIRECT_COMPLETE`` and ``DPM_FLAG_SMART_PREPARE`` driver + power management flags. [Typically, they are set at the time the driver + is probed against the device in question by passing them to the :c:func:`dev_pm_set_driver_flags` helper function.] If the first of these flags is set, the PM core will not apply the direct-complete procedure described above to the given device and, consequenty, to any diff --git a/Documentation/power/pci.rst b/Documentation/power/pci.rst index aa1c7fce6cd0..9e1408121bea 100644 --- a/Documentation/power/pci.rst +++ b/Documentation/power/pci.rst @@ -1004,11 +1004,11 @@ including the PCI bus type. The flags should be set once at the driver probe time with the help of the dev_pm_set_driver_flags() function and they should not be updated directly afterwards. -The DPM_FLAG_NEVER_SKIP flag prevents the PM core from using the direct-complete -mechanism allowing device suspend/resume callbacks to be skipped if the device -is in runtime suspend when the system suspend starts. That also affects all of -the ancestors of the device, so this flag should only be used if absolutely -necessary. +The DPM_FLAG_NO_DIRECT_COMPLETE flag prevents the PM core from using the +direct-complete mechanism allowing device suspend/resume callbacks to be skipped +if the device is in runtime suspend when the system suspend starts. That also +affects all of the ancestors of the device, so this flag should only be used if +absolutely necessary. The DPM_FLAG_SMART_PREPARE flag instructs the PCI bus type to only return a positive value from pci_pm_prepare() if the ->prepare callback provided by the diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 21187ee37b22..aa9c8df9fc4b 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -1850,7 +1850,7 @@ static int device_prepare(struct device *dev, pm_message_t state) spin_lock_irq(&dev->power.lock); dev->power.direct_complete = state.event == PM_EVENT_SUSPEND && (ret > 0 || dev->power.no_pm_callbacks) && - !dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP); + !dev_pm_test_driver_flags(dev, DPM_FLAG_NO_DIRECT_COMPLETE); spin_unlock_irq(&dev->power.lock); return 0; } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c index fd1dc3236eca..a9086ea1ab60 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c @@ -191,7 +191,7 @@ int amdgpu_driver_load_kms(struct drm_device *dev, unsigned long flags) } if (adev->runpm) { - dev_pm_set_driver_flags(dev->dev, DPM_FLAG_NEVER_SKIP); + dev_pm_set_driver_flags(dev->dev, DPM_FLAG_NO_DIRECT_COMPLETE); pm_runtime_use_autosuspend(dev->dev); pm_runtime_set_autosuspend_delay(dev->dev, 5000); pm_runtime_set_active(dev->dev); diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index ad719c9602af..9cb2d7548daa 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -549,7 +549,7 @@ void intel_runtime_pm_enable(struct intel_runtime_pm *rpm) * becaue the HDA driver may require us to enable the audio power * domain during system suspend. */ - dev_pm_set_driver_flags(kdev, DPM_FLAG_NEVER_SKIP); + dev_pm_set_driver_flags(kdev, DPM_FLAG_NO_DIRECT_COMPLETE); pm_runtime_set_autosuspend_delay(kdev, 10000); /* 10s */ pm_runtime_mark_last_busy(kdev); diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c index 58176db85952..372962358a18 100644 --- a/drivers/gpu/drm/radeon/radeon_kms.c +++ b/drivers/gpu/drm/radeon/radeon_kms.c @@ -158,7 +158,7 @@ int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags) } if (radeon_is_px(dev)) { - dev_pm_set_driver_flags(dev->dev, DPM_FLAG_NEVER_SKIP); + dev_pm_set_driver_flags(dev->dev, DPM_FLAG_NO_DIRECT_COMPLETE); pm_runtime_use_autosuspend(dev->dev); pm_runtime_set_autosuspend_delay(dev->dev, 5000); pm_runtime_set_active(dev->dev); diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c index 3d21c38e2dbb..53f16f3bd091 100644 --- a/drivers/misc/mei/pci-me.c +++ b/drivers/misc/mei/pci-me.c @@ -240,7 +240,7 @@ static int mei_me_probe(struct pci_dev *pdev, const struct pci_device_id *ent) * MEI requires to resume from runtime suspend mode * in order to perform link reset flow upon system suspend. */ - dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NEVER_SKIP); + dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE); /* * ME maps runtime suspend/resume to D0i states, diff --git a/drivers/misc/mei/pci-txe.c b/drivers/misc/mei/pci-txe.c index beacf2a2f2b5..4bf26ce61044 100644 --- a/drivers/misc/mei/pci-txe.c +++ b/drivers/misc/mei/pci-txe.c @@ -128,7 +128,7 @@ static int mei_txe_probe(struct pci_dev *pdev, const struct pci_device_id *ent) * MEI requires to resume from runtime suspend mode * in order to perform link reset flow upon system suspend. */ - dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NEVER_SKIP); + dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE); /* * TXE maps runtime suspend/resume to own power gating states, diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 177c6da80c57..2730b1c7dddb 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -7549,7 +7549,7 @@ static int e1000_probe(struct pci_dev *pdev, const struct pci_device_id *ent) e1000_print_device_info(adapter); - dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NEVER_SKIP); + dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE); if (pci_dev_run_wake(pdev) && hw->mac.type < e1000_pch_cnp) pm_runtime_put_noidle(&pdev->dev); diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index b46bff8fe056..8bb3db2cbd41 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -3445,7 +3445,7 @@ static int igb_probe(struct pci_dev *pdev, const struct pci_device_id *ent) } } - dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NEVER_SKIP); + dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE); pm_runtime_put_noidle(&pdev->dev); return 0; diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 69fa1ce1f927..59fc0097438f 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -4825,7 +4825,7 @@ static int igc_probe(struct pci_dev *pdev, pcie_print_link_status(pdev); netdev_info(netdev, "MAC: %pM\n", netdev->dev_addr); - dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NEVER_SKIP); + dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE); pm_runtime_put_noidle(&pdev->dev); diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index 160d67c59310..3acf151ae015 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -115,7 +115,7 @@ static int pcie_portdrv_probe(struct pci_dev *dev, pci_save_state(dev); - dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_NEVER_SKIP | + dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_NO_DIRECT_COMPLETE | DPM_FLAG_SMART_SUSPEND); if (pci_bridge_d3_possible(dev)) { diff --git a/include/linux/pm.h b/include/linux/pm.h index d89b7099f241..28fd444fb5c9 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -544,7 +544,7 @@ struct pm_subsys_data { * These flags can be set by device drivers at the probe time. They need not be * cleared by the drivers as the driver core will take care of that. * - * NEVER_SKIP: Do not skip all system suspend/resume callbacks for the device. + * NO_DIRECT_COMPLETE: Do not apply direct-complete optimization to the device. * SMART_PREPARE: Check the return value of the driver's ->prepare callback. * SMART_SUSPEND: No need to resume the device from runtime suspend. * LEAVE_SUSPENDED: Avoid resuming the device during system resume if possible. @@ -554,7 +554,7 @@ struct pm_subsys_data { * their ->prepare callbacks if the driver's ->prepare callback returns 0 (in * other words, the system suspend/resume callbacks can only be skipped for the * device if its driver doesn't object against that). This flag has no effect - * if NEVER_SKIP is set. + * if NO_DIRECT_COMPLETE is set. * * Setting SMART_SUSPEND instructs bus types and PM domains which may want to * runtime resume the device upfront during system suspend that doing so is not @@ -565,7 +565,7 @@ struct pm_subsys_data { * Setting LEAVE_SUSPENDED informs the PM core and middle-layer code that the * driver prefers the device to be left in suspend after system resume. */ -#define DPM_FLAG_NEVER_SKIP BIT(0) +#define DPM_FLAG_NO_DIRECT_COMPLETE BIT(0) #define DPM_FLAG_SMART_PREPARE BIT(1) #define DPM_FLAG_SMART_SUSPEND BIT(2) #define DPM_FLAG_LEAVE_SUSPENDED BIT(3) From patchwork Fri Apr 10 15:57:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11483375 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 759ED1892 for ; Fri, 10 Apr 2020 16:00:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A27420757 for ; Fri, 10 Apr 2020 16:00:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726682AbgDJQAt (ORCPT ); Fri, 10 Apr 2020 12:00:49 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:61530 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726203AbgDJQAs (ORCPT ); Fri, 10 Apr 2020 12:00:48 -0400 Received: from 185.80.35.16 (185.80.35.16) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.415) id efbcdca732cb25c5; Fri, 10 Apr 2020 18:00:46 +0200 From: "Rafael J. Wysocki" To: Linux PM , Alan Stern Cc: Linux ACPI , Linux PCI , LKML , Bjorn Helgaas , Greg Kroah-Hartman , Mika Westerberg , Hans De Goede , Ulf Hansson , Linux ACPI , Linux I2C , Linux PCI Subject: [PATCH 6/7] PM: sleep: core: Rename DPM_FLAG_LEAVE_SUSPENDED Date: Fri, 10 Apr 2020 17:57:49 +0200 Message-ID: <11863688.3RhLv4JJn2@kreacher> In-Reply-To: <1888197.j9z7NJ8yPn@kreacher> References: <1888197.j9z7NJ8yPn@kreacher> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: "Rafael J. Wysocki" Rename DPM_FLAG_LEAVE_SUSPENDED to DPM_FLAG_MAY_SKIP_RESUME which matches its purpose more closely. No functional impact. Signed-off-by: Rafael J. Wysocki Acked-by: Wolfram Sang # for I2C --- Documentation/driver-api/pm/devices.rst | 4 ++-- Documentation/power/pci.rst | 2 +- drivers/acpi/acpi_tad.c | 2 +- drivers/base/power/main.c | 2 +- drivers/i2c/busses/i2c-designware-platdrv.c | 2 +- include/linux/pm.h | 6 +++--- 6 files changed, 9 insertions(+), 9 deletions(-) diff --git a/Documentation/driver-api/pm/devices.rst b/Documentation/driver-api/pm/devices.rst index 4ace0eba4506..f342c7549b4c 100644 --- a/Documentation/driver-api/pm/devices.rst +++ b/Documentation/driver-api/pm/devices.rst @@ -803,7 +803,7 @@ general.] However, it often is desirable to leave devices in suspend after system transitions to the working state, especially if those devices had been in runtime suspend before the preceding system-wide suspend (or analogous) -transition. Device drivers can use the ``DPM_FLAG_LEAVE_SUSPENDED`` flag to +transition. Device drivers can use the ``DPM_FLAG_MAY_SKIP_RESUME`` flag to indicate to the PM core (and middle-layer code) that they prefer the specific devices handled by them to be left suspended and they have no problems with skipping their system-wide resume callbacks for this reason. Whether or not the @@ -825,7 +825,7 @@ device really can be left in suspend. For devices whose "noirq", "late" and "early" driver callbacks are invoked directly by the PM core, all of the system-wide resume callbacks are skipped if -``DPM_FLAG_LEAVE_SUSPENDED`` is set and the device is in runtime suspend during +``DPM_FLAG_MAY_SKIP_RESUME`` is set and the device is in runtime suspend during the ``suspend_noirq`` (or analogous) phase or the transition under way is a proper system suspend (rather than anything related to hibernation) and the device's wakeup settings are suitable for runtime PM (that is, it cannot diff --git a/Documentation/power/pci.rst b/Documentation/power/pci.rst index 9e1408121bea..f09b382b4621 100644 --- a/Documentation/power/pci.rst +++ b/Documentation/power/pci.rst @@ -1029,7 +1029,7 @@ into D0 going forward), but if it is in runtime suspend in pci_pm_thaw_noirq(), the function will set the power.direct_complete flag for it (to make the PM core skip the subsequent "thaw" callbacks for it) and return. -Setting the DPM_FLAG_LEAVE_SUSPENDED flag means that the driver prefers the +Setting the DPM_FLAG_MAY_SKIP_RESUME flag means that the driver prefers the device to be left in suspend after system-wide transitions to the working state. This flag is checked by the PM core, but the PCI bus type informs the PM core which devices may be left in suspend from its perspective (that happens during diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c index 33a4bcdaa4d7..7d45cce0c3c1 100644 --- a/drivers/acpi/acpi_tad.c +++ b/drivers/acpi/acpi_tad.c @@ -624,7 +624,7 @@ static int acpi_tad_probe(struct platform_device *pdev) */ device_init_wakeup(dev, true); dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND | - DPM_FLAG_LEAVE_SUSPENDED); + DPM_FLAG_MAY_SKIP_RESUME); /* * The platform bus type layer tells the ACPI PM domain powers up the * device, so set the runtime PM status of it to "active". diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index aa9c8df9fc4b..b6f785024b24 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -1247,7 +1247,7 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a * to be skipped. */ if (atomic_read(&dev->power.usage_count) > 1 || - !(dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED) && + !(dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME) && dev->power.may_skip_resume)) dev->power.must_resume = true; diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index c98befe2a92e..b6270e69f853 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -357,7 +357,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_SMART_PREPARE | DPM_FLAG_SMART_SUSPEND | - DPM_FLAG_LEAVE_SUSPENDED); + DPM_FLAG_MAY_SKIP_RESUME); /* The code below assumes runtime PM to be disabled. */ WARN_ON(pm_runtime_enabled(&pdev->dev)); diff --git a/include/linux/pm.h b/include/linux/pm.h index 28fd444fb5c9..f545666120d0 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -547,7 +547,7 @@ struct pm_subsys_data { * NO_DIRECT_COMPLETE: Do not apply direct-complete optimization to the device. * SMART_PREPARE: Check the return value of the driver's ->prepare callback. * SMART_SUSPEND: No need to resume the device from runtime suspend. - * LEAVE_SUSPENDED: Avoid resuming the device during system resume if possible. + * MAY_SKIP_RESUME: Avoid resuming the device during system resume if possible. * * Setting SMART_PREPARE instructs bus types and PM domains which may want * system suspend/resume callbacks to be skipped for the device to return 0 from @@ -562,13 +562,13 @@ struct pm_subsys_data { * invocations of the ->suspend_late and ->suspend_noirq callbacks provided by * the driver if they decide to leave the device in runtime suspend. * - * Setting LEAVE_SUSPENDED informs the PM core and middle-layer code that the + * Setting MAY_SKIP_RESUME informs the PM core and middle-layer code that the * driver prefers the device to be left in suspend after system resume. */ #define DPM_FLAG_NO_DIRECT_COMPLETE BIT(0) #define DPM_FLAG_SMART_PREPARE BIT(1) #define DPM_FLAG_SMART_SUSPEND BIT(2) -#define DPM_FLAG_LEAVE_SUSPENDED BIT(3) +#define DPM_FLAG_MAY_SKIP_RESUME BIT(3) struct dev_pm_info { pm_message_t power_state; From patchwork Fri Apr 10 15:58:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11483407 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F119D912 for ; Fri, 10 Apr 2020 16:01:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CBA8A214D8 for ; Fri, 10 Apr 2020 16:01:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726701AbgDJQAt (ORCPT ); Fri, 10 Apr 2020 12:00:49 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:41565 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726173AbgDJQAs (ORCPT ); Fri, 10 Apr 2020 12:00:48 -0400 Received: from 185.80.35.16 (185.80.35.16) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.415) id fa9d766f623ddf0c; Fri, 10 Apr 2020 18:00:45 +0200 From: "Rafael J. Wysocki" To: Linux PM , Alan Stern Cc: Linux ACPI , Linux PCI , LKML , Bjorn Helgaas , Greg Kroah-Hartman , Mika Westerberg , Hans De Goede , Ulf Hansson , Bjorn Helgaas , Linux PCI , Linux Documentation Subject: [PATCH 7/7] Documentation: PM: sleep: Update driver flags documentation Date: Fri, 10 Apr 2020 17:58:50 +0200 Message-ID: <1997182.shB3oO26W5@kreacher> In-Reply-To: <1888197.j9z7NJ8yPn@kreacher> References: <1888197.j9z7NJ8yPn@kreacher> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: "Rafael J. Wysocki" Update the documentation of the driver flags for system-wide power management to reflect the current code flows and be more consistent. Signed-off-by: Rafael J. Wysocki --- Documentation/driver-api/pm/devices.rst | 118 +++++++++++++++++++------------- Documentation/power/pci.rst | 43 ++++++------ include/linux/pm.h | 24 ++----- 3 files changed, 98 insertions(+), 87 deletions(-) diff --git a/Documentation/driver-api/pm/devices.rst b/Documentation/driver-api/pm/devices.rst index f342c7549b4c..39360c2cc54d 100644 --- a/Documentation/driver-api/pm/devices.rst +++ b/Documentation/driver-api/pm/devices.rst @@ -776,58 +776,82 @@ Some bus types and PM domains have a policy to resume all devices from runtime suspend upfront in their ``->suspend`` callbacks, but that may not be really necessary if the driver of the device can cope with runtime-suspended devices. The driver can indicate that by setting ``DPM_FLAG_SMART_SUSPEND`` in -:c:member:`power.driver_flags` at the probe time, by passing it to the -:c:func:`dev_pm_set_driver_flags` helper. That also may cause middle-layer code +:c:member:`power.driver_flags` at the probe time with the help of the +:c:func:`dev_pm_set_driver_flags` helper routine. + +However, setting that flag also causes the PM core and middle-layer code (bus types, PM domains etc.) to skip the ``->suspend_late`` and ``->suspend_noirq`` callbacks provided by the driver if the device remains in -runtime suspend at the beginning of the ``suspend_late`` phase of system-wide -suspend (or in the ``poweroff_late`` phase of hibernation), when runtime PM -has been disabled for it, under the assumption that its state should not change -after that point until the system-wide transition is over (the PM core itself -does that for devices whose "noirq", "late" and "early" system-wide PM callbacks -are executed directly by it). If that happens, the driver's system-wide resume -callbacks, if present, may still be invoked during the subsequent system-wide -resume transition and the device's runtime power management status may be set -to "active" before enabling runtime PM for it, so the driver must be prepared to -cope with the invocation of its system-wide resume callbacks back-to-back with -its ``->runtime_suspend`` one (without the intervening ``->runtime_resume`` and -so on) and the final state of the device must reflect the "active" runtime PM -status in that case. +runtime suspend during the ``suspend_late`` phase of system-wide suspend (or +during the ``poweroff_late`` or ``freeze_late`` phase of hibernation), +after runtime PM was disabled for it. [Without doing that, the same driver +callback might be executed twice in a row for the same device, which would not +be valid in general.] If the middle-layer system-wide PM callbacks are present +for the device, they are responsible for doing the above, and if they are not +present, the PM core takes care of it. + +In addition, with ``DPM_FLAG_SMART_SUSPEND`` set, the driver's ``->thaw_late`` +and ``->thaw_noirq`` callbacks are skipped if the device remained in runtime +suspend during the preceding "freeze" transition related to hibernation. +[Again, if the middle-layer callbacks are present for the device, they are +responsible for doing that, or the PM core takes care of it otherwise.] During system-wide resume from a sleep state it's easiest to put devices into the full-power state, as explained in :file:`Documentation/power/runtime_pm.rst`. [Refer to that document for more information regarding this particular issue as well as for information on the device runtime power management framework in -general.] - -However, it often is desirable to leave devices in suspend after system -transitions to the working state, especially if those devices had been in +general.] However, it often is desirable to leave devices in suspend after +system transitions to the working state, especially if those devices had been in runtime suspend before the preceding system-wide suspend (or analogous) -transition. Device drivers can use the ``DPM_FLAG_MAY_SKIP_RESUME`` flag to -indicate to the PM core (and middle-layer code) that they prefer the specific -devices handled by them to be left suspended and they have no problems with -skipping their system-wide resume callbacks for this reason. Whether or not the -devices will actually be left in suspend may depend on their state before the -given system suspend-resume cycle and on the type of the system transition under -way. In particular, devices are not left suspended if that transition is a -restore from hibernation, as device states are not guaranteed to be reflected -by the information stored in the hibernation image in that case. - -The middle-layer code involved in the handling of the device is expected to -indicate to the PM core if the device may be left in suspend by setting its -:c:member:`power.may_skip_resume` status bit which is checked by the PM core -during the "noirq" phase of the preceding system-wide suspend (or analogous) -transition. The middle layer is then responsible for handling the device as -appropriate in its "noirq" resume callback, which is executed regardless of -whether or not the device is left suspended, but the other resume callbacks -(except for ``->complete``) will be skipped automatically by the PM core if the -device really can be left in suspend. - -For devices whose "noirq", "late" and "early" driver callbacks are invoked -directly by the PM core, all of the system-wide resume callbacks are skipped if -``DPM_FLAG_MAY_SKIP_RESUME`` is set and the device is in runtime suspend during -the ``suspend_noirq`` (or analogous) phase or the transition under way is a -proper system suspend (rather than anything related to hibernation) and the -device's wakeup settings are suitable for runtime PM (that is, it cannot -generate wakeup signals at all or it is allowed to wake up the system from -sleep). +transition. + +To that end, device drivers can use the ``DPM_FLAG_MAY_SKIP_RESUME`` flag to +indicate to the PM core and middle-layer code that they allow their "noirq" and +"early" resume callbacks to be skipped if the device can be left in suspend +after system-wide PM transitions to the working state. Whether or not that is +the case generally depend on the state of the device before the given system +suspend-resume cycle and on the type of the system transition under way. +In particular, driver callbacks are never skipped during the "restore" +transition related to hibernation (because the actual states of devices at that +time are not known in general, all of them are put into the full-power state +then and configured to reflect their "active" working-state settings). + +The middle-layer code is expected to indicate to the PM core whether or not +skipping the driver's "noirq" and "early" resume callbacks for a given device +makes sense from its perspective by either setting or clearing the device's +:c:member:`power.may_skip_resume` status bit (checked by the PM core during the +"noirq" phase of the suspend, or analogous, transition). Setting that status +bit along with the ``DPM_FLAG_MAY_SKIP_RESUME`` flag is necessary, but +generally not sufficient, for the driver's "noirq" and "early" callbacks to be +skipped. Whether or not they should be skipped can be determined by evaluating +the :c:func:`dev_pm_skip_resume` helper function. + +If that function returns ``true``, the driver's "noirq" and "early" resume +callbacks should be skipped. Otherwise, if the device was runtime-suspended +during the preceding system-wide suspend transition, its runtime PM status needs +to be set to "active" which is taken care of by the PM core. + +If the ``DPM_FLAG_MAY_SKIP_RESUME`` flag is not set for a device, but +``DPM_FLAG_SMART_SUSPEND`` is set and the driver's "late" and "noirq" suspend +callbacks are skipped, its system-wide "noirq" and "early" resume callbacks, if +present, are invoked as usual and the device's runtime PM status is set to +"active" by the PM core before enabling runtime PM for it, so the driver must be +prepared to cope with the invocation of its system-wide resume callbacks +back-to-back with its ``->runtime_suspend`` one (without the intervening +``->runtime_resume`` and system-wide suspend callbacks) and the final state of +the device must reflect the "active" runtime PM status in that case. [Note that +this is not a problem at all if the driver's ``->suspend_late`` callback pointer +points to the same function as its ``->runtime_suspend`` one and its +``->resume_early`` callback pointer points to the same function as the +``->runtime_resume`` one, while none of the other system-wide suspend-resume +callbacks of the driver are present, for example.] + +Likewise, if ``DPM_FLAG_MAY_SKIP_RESUME`` is set for a device, its driver's +system-wide "noirq" and "early" resume callbacks may be skipped while its "late" +and "noirq" suspend callbacks may have been executed (in principle, regardless +of whether or not ``DPM_FLAG_SMART_SUSPEND`` is set). In that case, the driver +needs to be able to cope with the invocation of its ``->runtime_resume`` +callback back-to-back with its "late" and "noirq" suspend ones. [Again, that +is not a concern if the driver sets both ``DPM_FLAG_SMART_SUSPEND`` and +``DPM_FLAG_MAY_SKIP_RESUME`` and uses the same pair of suspend/resume callback +functions for runtime PM and system-wide suspend/resume.] diff --git a/Documentation/power/pci.rst b/Documentation/power/pci.rst index f09b382b4621..1831e431f725 100644 --- a/Documentation/power/pci.rst +++ b/Documentation/power/pci.rst @@ -1010,32 +1010,33 @@ if the device is in runtime suspend when the system suspend starts. That also affects all of the ancestors of the device, so this flag should only be used if absolutely necessary. -The DPM_FLAG_SMART_PREPARE flag instructs the PCI bus type to only return a -positive value from pci_pm_prepare() if the ->prepare callback provided by the +The DPM_FLAG_SMART_PREPARE flag causes the PCI bus type to return a positive +value from pci_pm_prepare() only if the ->prepare callback provided by the driver of the device returns a positive value. That allows the driver to opt -out from using the direct-complete mechanism dynamically. +out from using the direct-complete mechanism dynamically (whereas setting +DPM_FLAG_NO_DIRECT_COMPLETE means permanent opt-out). The DPM_FLAG_SMART_SUSPEND flag tells the PCI bus type that from the driver's perspective the device can be safely left in runtime suspend during system suspend. That causes pci_pm_suspend(), pci_pm_freeze() and pci_pm_poweroff() -to skip resuming the device from runtime suspend unless there are PCI-specific -reasons for doing that. Also, it causes pci_pm_suspend_late/noirq(), -pci_pm_freeze_late/noirq() and pci_pm_poweroff_late/noirq() to return early -if the device remains in runtime suspend in the beginning of the "late" phase -of the system-wide transition under way. Moreover, if the device is in -runtime suspend in pci_pm_resume_noirq() or pci_pm_restore_noirq(), its runtime -power management status will be changed to "active" (as it is going to be put -into D0 going forward), but if it is in runtime suspend in pci_pm_thaw_noirq(), -the function will set the power.direct_complete flag for it (to make the PM core -skip the subsequent "thaw" callbacks for it) and return. - -Setting the DPM_FLAG_MAY_SKIP_RESUME flag means that the driver prefers the -device to be left in suspend after system-wide transitions to the working state. -This flag is checked by the PM core, but the PCI bus type informs the PM core -which devices may be left in suspend from its perspective (that happens during -the "noirq" phase of system-wide suspend and analogous transitions) and next it -uses the dev_pm_skip_resume() helper to decide whether or not to return from -pci_pm_resume_noirq() and pci_pm_resume_early() upfront. +to avoid resuming the device from runtime suspend unless there are PCI-specific +reasons for doing that. Also, it causes pci_pm_suspend_late/noirq() and +pci_pm_poweroff_late/noirq() to return early if the device remains in runtime +suspend during the "late" phase of the system-wide transition under way. +Moreover, if the device is in runtime suspend in pci_pm_resume_noirq() or +pci_pm_restore_noirq(), its runtime PM status will be changed to "active" (as it +is going to be put into D0 going forward). + +Setting the DPM_FLAG_MAY_SKIP_RESUME flag means that the driver allows its +"noirq" and "early" resume callbacks to be skipped if the device can be left +in suspend after a system-wide transition into the working state. This flag is +taken into consideration by the PM core along with the power.may_skip_resume +status bit of the device which is set by pci_pm_suspend_noirq() in certain +situations. If the PM core determines that the driver's "noirq" and "early" +resume callbacks should be skipped, the dev_pm_skip_resume() helper function +will return "true" and that will cause pci_pm_resume_noirq() and +pci_pm_resume_early() to return upfront without touching the device and +executing the driver callbacks. 3.2. Device Runtime Power Management ------------------------------------ diff --git a/include/linux/pm.h b/include/linux/pm.h index f545666120d0..9542bbc5f938 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -545,25 +545,11 @@ struct pm_subsys_data { * cleared by the drivers as the driver core will take care of that. * * NO_DIRECT_COMPLETE: Do not apply direct-complete optimization to the device. - * SMART_PREPARE: Check the return value of the driver's ->prepare callback. - * SMART_SUSPEND: No need to resume the device from runtime suspend. - * MAY_SKIP_RESUME: Avoid resuming the device during system resume if possible. - * - * Setting SMART_PREPARE instructs bus types and PM domains which may want - * system suspend/resume callbacks to be skipped for the device to return 0 from - * their ->prepare callbacks if the driver's ->prepare callback returns 0 (in - * other words, the system suspend/resume callbacks can only be skipped for the - * device if its driver doesn't object against that). This flag has no effect - * if NO_DIRECT_COMPLETE is set. - * - * Setting SMART_SUSPEND instructs bus types and PM domains which may want to - * runtime resume the device upfront during system suspend that doing so is not - * necessary from the driver's perspective. It also may cause them to skip - * invocations of the ->suspend_late and ->suspend_noirq callbacks provided by - * the driver if they decide to leave the device in runtime suspend. - * - * Setting MAY_SKIP_RESUME informs the PM core and middle-layer code that the - * driver prefers the device to be left in suspend after system resume. + * SMART_PREPARE: Take the driver ->prepare callback return value into account. + * SMART_SUSPEND: Avoid resuming the device from runtime suspend. + * MAY_SKIP_RESUME: Allow driver "noirq" and "early" callbacks to be skipped. + * + * See Documentation/driver-api/pm/devices.rst for details. */ #define DPM_FLAG_NO_DIRECT_COMPLETE BIT(0) #define DPM_FLAG_SMART_PREPARE BIT(1)