From patchwork Tue Apr 23 23:39:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Furquan Shaikh X-Patchwork-Id: 10913875 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9247E1390 for ; Tue, 23 Apr 2019 23:39:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 812E7289F0 for ; Tue, 23 Apr 2019 23:39:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 741FA289F2; Tue, 23 Apr 2019 23:39:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D99ED289F0 for ; Tue, 23 Apr 2019 23:39:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728703AbfDWXjJ (ORCPT ); Tue, 23 Apr 2019 19:39:09 -0400 Received: from mail-pf1-f201.google.com ([209.85.210.201]:40537 "EHLO mail-pf1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727045AbfDWXjI (ORCPT ); Tue, 23 Apr 2019 19:39:08 -0400 Received: by mail-pf1-f201.google.com with SMTP id f7so10602678pfd.7 for ; Tue, 23 Apr 2019 16:39:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=l4OycizyA4U5EtUwbs2RVj8M0wcMjT611kVIFhqJjMU=; b=QH7dpM/SPdEFshWf4Mox3ZzVJQDJ5EjmxAPm9CViy7vNKZKTZSsuzbqVqa+yAUbN5i q+NfU8bxXL5B417KaRqB0pSg2VvE55NkQmX1wgUDlhGS4shPCgR+lVtAsf5jsA0Zguii 1vlGQQNGACiXUg4uFsW7pl+VMNB2OsH7SD7CUR9KU9m4Yxj+NMzDe567aWJsk6ZCP3Lt bcikSyzfHb8+P+mGDPk1FtMNMgIrAQyAIW7eQC26t7+phIZ8UInHw/mi23T6M1ZzNsBY Yku94h8mTrlbFecKDUjXOF+YzDQ+d0NamOgW9HwVvdRGuMBPlegY3A6xWMbJRF3ER/ci pKhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=l4OycizyA4U5EtUwbs2RVj8M0wcMjT611kVIFhqJjMU=; b=ctiAfrlsm0TCEF0Iwg35vPcB+uNrUBJrEN9bnsThR6wLOsRDlolQUlALqmbQTUanbW +1HeGo23DgnRnT84fvBBEQ3qV7ZJhQV/zbSNAxcVLdTN2/wCoUSMmqqs/0waKntGvG2B KOd15gCP5vd6AbifTuqeCWtdx+ilYJsKqv/ydMHDdPYFgWzz8ign5kF3WnfYwudyo/EA XJOZ/yXFnyNzY1519VqlyYxvtIsCiprsGCEkm49S1OxO2CsQ/KopGccOhANW30fCbvLQ m2npMGKAa2XSmAEg6qHkzA29zgP0tBWjNyj0Qe7Y2Z4aqTYG7z1FIpBca71t55LlQr8C 7GCw== X-Gm-Message-State: APjAAAXvc+vN5M1nK1z2+Dhu8NsX7Dc84+/cnqXbR1on9n6QBN2UVk6b /KUdPsiZA3Aae2iogGdf1e2FWlYPYpcd X-Google-Smtp-Source: APXvYqyfHcPeX7FpqyI0kp5JyjYb+VFFph0EunyTXyIbwVSLwBz+WWvAWSJgxWAonkxGhy7Gd0QmacvjAU+j X-Received: by 2002:a63:20f:: with SMTP id 15mr26489675pgc.90.1556062747616; Tue, 23 Apr 2019 16:39:07 -0700 (PDT) Date: Tue, 23 Apr 2019 16:39:04 -0700 Message-Id: <20190423233904.195842-1-furquan@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.21.0.593.g511ec345e18-goog Subject: [PATCH] drivers/acpi: Turn off power resources while entering S5 From: Furquan Shaikh To: "Rafael J . Wysocki" , Len Brown Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, rajatja@google.com, dlaurie@google.com, furquan@google.com Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP During boot-up, ACPI bus scan enables all power resources so that respective device drivers can talk to their device. This causes acpi ref_count for the power resource to be incremented to 1. When system suspends (S3/S0ix) or hibernates(S4), DPM is responsible for calling power off on all power resources whose ref_count is 1 i.e. no other user of this power resource and thus resulting in _OFF routine being called for it. However, in case of poweroff, DPM is not involved and so the power resources are left on when the system is entering S5. This results in the violation of power down sequencing for certain devices e.g. touchscreen or digitizer I2C devices. In order to ensure that the power down sequencing does the right thing, it is necessary for ACPI to disable all power resources while preparing for S5. This change updates the function acpi_turn_off_unused_power_resources to accept a parameter acpi_system_state, This function turns off power resources according to the targeted system ACPI state: 1. For S0: Unused power resources are turned off i.e. power resources whose ref_count is already 0. 2. For S5: ref_count is decremented first to undo the increment performed during ACPI bus scan and then power resources with ref_count 0 are turned off. 3. All other suspend/hibernate states: No action is required since DPM takes care of turning off power resources. This change should not affect the wake capable devices since: 1. If wake capable devices are enabled before this call, their refcount should be greater than 1. Thus, they won't be turned off. 2. If wake capable devices are not enabled yet when this call is made, they would eventually get turned on by call to acpi_enable_wakeup_devices. Signed-off-by: Furquan Shaikh --- drivers/acpi/power.c | 47 ++++++++++++++++++++++++++++++++++++++------ drivers/acpi/sleep.c | 5 ++++- drivers/acpi/sleep.h | 2 +- 3 files changed, 46 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index 665e93ca0b40f..945db762861a3 100644 --- a/drivers/acpi/power.c +++ b/drivers/acpi/power.c @@ -889,10 +889,42 @@ void acpi_resume_power_resources(void) mutex_unlock(&power_resource_list_lock); } +#endif -void acpi_turn_off_unused_power_resources(void) +/** + * acpi_turn_off_power_resources: This function is used to turn off power + * resources in provided ACPI system state. + * + * Behavior differs based on the target system state: + * ACPI_STATE_S0: Turn off unused power resources i.e. turn off power resources + * with ref_count zero. + * ACPI_STATE_S5: Decrement ref_count first and turn off power resources with + * ref_count zero. This is done to ensure that the ref_count + * incremented during ACPI bus scan is undone and any power + * resources that are not required during S5 are turned off. + * ACPI_STATE_Sx: No action required. DPM is responsible for turning off power + * resources while suspending/hibernating. + */ +void acpi_turn_off_power_resources(int acpi_system_state) { struct acpi_power_resource *resource; + int decrement; + + if (acpi_system_state == ACPI_STATE_S0) { + /* + * In case of ACPI_STATE_S0, turn off only unused power + * resources. So, no need to decrement ref_count. + */ + decrement = 0; + } else if (acpi_system_state == ACPI_STATE_S5) { + /* + * In case of ACPI_STATE_S5, ref_count needs to be decremented + * first before checking if it is okay to power off the + * resource. + */ + decrement = 1; + } else + return; mutex_lock(&power_resource_list_lock); @@ -907,10 +939,14 @@ void acpi_turn_off_unused_power_resources(void) continue; } - if (state == ACPI_POWER_RESOURCE_STATE_ON - && !resource->ref_count) { - dev_info(&resource->device.dev, "Turning OFF\n"); - __acpi_power_off(resource); + if (state == ACPI_POWER_RESOURCE_STATE_ON) { + if (resource->ref_count) + resource->ref_count -= decrement; + + if (!resource->ref_count) { + dev_info(&resource->device.dev, "Turning OFF\n"); + __acpi_power_off(resource); + } } mutex_unlock(&resource->resource_lock); @@ -918,4 +954,3 @@ void acpi_turn_off_unused_power_resources(void) mutex_unlock(&power_resource_list_lock); } -#endif diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index 403c4ff153498..fb6b3ca0eeb91 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -75,6 +75,9 @@ static int acpi_sleep_prepare(u32 acpi_state) printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n", acpi_state); acpi_enable_wakeup_devices(acpi_state); + + acpi_turn_off_power_resources(acpi_state); + acpi_enter_sleep_state_prep(acpi_state); return 0; } @@ -524,7 +527,7 @@ static void acpi_pm_start(u32 acpi_state) */ static void acpi_pm_end(void) { - acpi_turn_off_unused_power_resources(); + acpi_turn_off_power_resources(ACPI_STATE_S0); acpi_scan_lock_release(); /* * This is necessary in case acpi_pm_finish() is not called during a diff --git a/drivers/acpi/sleep.h b/drivers/acpi/sleep.h index 41675d24a9bc0..a495c91e2bf3b 100644 --- a/drivers/acpi/sleep.h +++ b/drivers/acpi/sleep.h @@ -7,7 +7,7 @@ extern struct list_head acpi_wakeup_device_list; extern struct mutex acpi_device_lock; extern void acpi_resume_power_resources(void); -extern void acpi_turn_off_unused_power_resources(void); +extern void acpi_turn_off_power_resources(int acpi_system_state); static inline acpi_status acpi_set_waking_vector(u32 wakeup_address) {