From patchwork Fri Feb 1 00:59:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 10791649 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 244A914E1 for ; Fri, 1 Feb 2019 01:04:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 079612883D for ; Fri, 1 Feb 2019 01:04:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EC76928AA2; Fri, 1 Feb 2019 01:04:01 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI 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 2338A2883D for ; Fri, 1 Feb 2019 01:04:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725963AbfBABEA (ORCPT ); Thu, 31 Jan 2019 20:04:00 -0500 Received: from cloudserver094114.home.pl ([79.96.170.134]:53289 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725787AbfBABEA (ORCPT ); Thu, 31 Jan 2019 20:04:00 -0500 Received: from 79.184.255.169.ipv4.supernova.orange.pl (79.184.255.169) (HELO aspire.rjw.lan) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.183) id 55591e85b9d32e01; Fri, 1 Feb 2019 02:03:57 +0100 From: "Rafael J. Wysocki" To: Greg Kroah-Hartman Cc: LKML , Linux PM , Ulf Hansson , Daniel Vetter , Lukas Wunner , Andrzej Hajda , Russell King - ARM Linux , Lucas Stach , Linus Walleij , Thierry Reding , Laurent Pinchart , Marek Szyprowski , Joerg Roedel Subject: [PATCH v2 9/9] driver core: Add device link flag DL_FLAG_AUTOPROBE_CONSUMER Date: Fri, 01 Feb 2019 01:59:42 +0100 Message-ID: <2385908.xrJhg5KmqK@aspire.rjw.lan> In-Reply-To: <1952449.TVsm6CJCTy@aspire.rjw.lan> References: <1952449.TVsm6CJCTy@aspire.rjw.lan> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rafael J. Wysocki Add a new device link flag, DL_FLAG_AUTOPROBE_CONSUMER, to request the driver core to probe for a consumer driver automatically after binding a driver to the supplier device on a persistent managed device link. As unbinding the supplier driver on a managed device link causes the consumer driver to be detached from its device automatically, this flag provides a complementary mechanism which is needed to address some "composite device" use cases. Signed-off-by: Rafael J. Wysocki --- Documentation/driver-api/device_link.rst | 9 +++++++++ drivers/base/core.c | 16 +++++++++++++++- drivers/base/dd.c | 2 +- include/linux/device.h | 3 +++ 4 files changed, 28 insertions(+), 2 deletions(-) Index: linux-pm/include/linux/device.h =================================================================== --- linux-pm.orig/include/linux/device.h +++ linux-pm/include/linux/device.h @@ -341,6 +341,7 @@ struct device *driver_find_device(struct struct device *start, void *data, int (*match)(struct device *dev, void *data)); +void driver_deferred_probe_add(struct device *dev); int driver_deferred_probe_check_state(struct device *dev); /** @@ -827,12 +828,14 @@ enum device_link_state { * PM_RUNTIME: If set, the runtime PM framework will use this link. * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation. * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind. + * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds. */ #define DL_FLAG_STATELESS BIT(0) #define DL_FLAG_AUTOREMOVE_CONSUMER BIT(1) #define DL_FLAG_PM_RUNTIME BIT(2) #define DL_FLAG_RPM_ACTIVE BIT(3) #define DL_FLAG_AUTOREMOVE_SUPPLIER BIT(4) +#define DL_FLAG_AUTOPROBE_CONSUMER BIT(5) /** * struct device_link - Device link representation. Index: linux-pm/drivers/base/core.c =================================================================== --- linux-pm.orig/drivers/base/core.c +++ linux-pm/drivers/base/core.c @@ -208,6 +208,12 @@ static void device_link_rpm_prepare(stru * the link will be maintained until one of the devices pointed to by it (either * the consumer or the supplier) is unregistered. * + * Also, if DL_FLAG_STATELESS, DL_FLAG_AUTOREMOVE_CONSUMER and + * DL_FLAG_AUTOREMOVE_SUPPLIER are not set in @flags (that is, a persistent + * managed device link is being added), the DL_FLAG_AUTOPROBE_CONSUMER flag can + * be used to request the driver core to automaticall probe for a consmer + * driver after successfully binding a driver to the supplier device. + * * The combination of DL_FLAG_STATELESS and either DL_FLAG_AUTOREMOVE_CONSUMER * or DL_FLAG_AUTOREMOVE_SUPPLIER set in @flags at the same time is invalid and * will cause NULL to be returned upfront. @@ -228,7 +234,12 @@ struct device_link *device_link_add(stru if (!consumer || !supplier || (flags & DL_FLAG_STATELESS && - flags & (DL_FLAG_AUTOREMOVE_CONSUMER | DL_FLAG_AUTOREMOVE_SUPPLIER))) + flags & (DL_FLAG_AUTOREMOVE_CONSUMER | + DL_FLAG_AUTOREMOVE_SUPPLIER | + DL_FLAG_AUTOPROBE_CONSUMER)) || + (flags & DL_FLAG_AUTOPROBE_CONSUMER && + flags & (DL_FLAG_AUTOREMOVE_CONSUMER | + DL_FLAG_AUTOREMOVE_SUPPLIER))) return NULL; if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) { @@ -589,6 +600,9 @@ void device_links_driver_bound(struct de WARN_ON(link->status != DL_STATE_DORMANT); WRITE_ONCE(link->status, DL_STATE_AVAILABLE); + + if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER) + driver_deferred_probe_add(link->consumer); } list_for_each_entry(link, &dev->links.suppliers, c_node) { Index: linux-pm/drivers/base/dd.c =================================================================== --- linux-pm.orig/drivers/base/dd.c +++ linux-pm/drivers/base/dd.c @@ -116,7 +116,7 @@ static void deferred_probe_work_func(str } static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func); -static void driver_deferred_probe_add(struct device *dev) +void driver_deferred_probe_add(struct device *dev) { mutex_lock(&deferred_probe_mutex); if (list_empty(&dev->p->deferred_probe)) { Index: linux-pm/Documentation/driver-api/device_link.rst =================================================================== --- linux-pm.orig/Documentation/driver-api/device_link.rst +++ linux-pm/Documentation/driver-api/device_link.rst @@ -94,6 +94,15 @@ Similarly, when the device link is added ``DL_FLAG_AUTOREMOVE_SUPPLIER`` causes the device link to be automatically purged when the supplier fails to probe or later unbinds. +If neither ``DL_FLAG_AUTOREMOVE_CONSUMER`` nor ``DL_FLAG_AUTOREMOVE_SUPPLIER`` +is set, ``DL_FLAG_AUTOPROBE_CONSUMER`` can be used to request the driver core +to probe for a driver for the consumer driver on the link automatically after +a driver has been bound to the supplier device. + +Note, however, that any combinations of ``DL_FLAG_AUTOREMOVE_CONSUMER``, +``DL_FLAG_AUTOREMOVE_SUPPLIER`` or ``DL_FLAG_AUTOPROBE_CONSUMER`` with +``DL_FLAG_STATELESS`` are invalid and cannot be used. + Limitations ===========