From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753782AbaBPXjh (ORCPT ); Sun, 16 Feb 2014 18:39:37 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:63703 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752883AbaBPXij (ORCPT ); Sun, 16 Feb 2014 18:38:39 -0500 From: "Rafael J. Wysocki" To: Linux PM list Cc: Alan Stern , Mika Westerberg , Aaron Lu , ACPI Devel Maling List , LKML Subject: [PATCH 1/3] PM / sleep: New flag to speed up suspend-resume of suspended devices Date: Mon, 17 Feb 2014 00:50:39 +0100 Message-ID: <21442757.ztmIxNHa8O@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.13.0+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1829141.MEZji1aIKp@vostro.rjw.lan> References: <5420830.W4laSGaAU9@vostro.rjw.lan> <1829141.MEZji1aIKp@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki Currently, some subsystems (e.g. PCI and the ACPI PM domain) have to resume all runtime-suspended devices during system suspend, mostly because those devices may need to be reprogrammed due to different wakeup settings for system sleep and for runtime PM. However, at least in some cases, that isn't really necessary, because the wakeup settings may not be really different. The idea here is that subsystems should know whether or not it is necessary to reprogram a given device during system suspend and they should be able to tell the PM core about that. For this reason, modify the PM core so that if the .prepare() callback returns a positive value for certain device, the core will set a new power.fast_suspend flag for it. Then, if that flag is set, the core will skip all of the subsequent suspend callbacks for that device. It also will skip all of the system resume callbacks for the device during the subsequent system resume and pm_request_resume() will be executed to trigger a runtime PM resume of the device after the system device resume sequence has been finished. However, since parents may need to be resumed so that their children can be reprogrammed, make the PM core clear power.fast_suspend for devices whose children don't have power.fast_suspend set (the power.ignore_children flag doesn't matter here, because a parent whose children are normally ignored for runtime PM may still need to be accessible for their children to be prepare for system suspend properly). Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 49 +++++++++++++++++++++++++++++++--------------- include/linux/pm.h | 1 2 files changed, 35 insertions(+), 15 deletions(-) Index: linux-pm/drivers/base/power/main.c =================================================================== --- linux-pm.orig/drivers/base/power/main.c +++ linux-pm/drivers/base/power/main.c @@ -478,7 +478,7 @@ static int device_resume_noirq(struct de TRACE_DEVICE(dev); TRACE_RESUME(0); - if (dev->power.syscore) + if (dev->power.syscore || dev->power.fast_suspend) goto Out; if (!dev->power.is_noirq_suspended) @@ -599,7 +599,7 @@ static int device_resume_early(struct de TRACE_DEVICE(dev); TRACE_RESUME(0); - if (dev->power.syscore) + if (dev->power.syscore || dev->power.fast_suspend) goto Out; if (!dev->power.is_late_suspended) @@ -724,6 +724,11 @@ static int device_resume(struct device * if (dev->power.syscore) goto Complete; + if (dev->power.fast_suspend) { + pm_request_resume(dev); + goto Complete; + } + dpm_wait(dev->parent, async); dpm_watchdog_set(&wd, dev); device_lock(dev); @@ -994,7 +999,7 @@ static int __device_suspend_noirq(struct return async_error; } - if (dev->power.syscore) + if (dev->power.syscore || dev->power.fast_suspend) return 0; if (dev->pm_domain) { @@ -1127,7 +1132,7 @@ static int __device_suspend_late(struct return async_error; } - if (dev->power.syscore) + if (dev->power.syscore || dev->power.fast_suspend) return 0; if (dev->pm_domain) { @@ -1296,8 +1301,10 @@ static int __device_suspend(struct devic * for it, this is equivalent to the device signaling wakeup, so the * system suspend operation should be aborted. */ - if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) + if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) { pm_wakeup_event(dev, 0); + dev->power.fast_suspend = false; + } if (pm_wakeup_pending()) { async_error = -EBUSY; @@ -1310,6 +1317,9 @@ static int __device_suspend(struct devic dpm_watchdog_set(&wd, dev); device_lock(dev); + if (dev->power.fast_suspend) + goto End; + if (dev->pm_domain) { info = "power domain "; callback = pm_op(&dev->pm_domain->ops, state); @@ -1358,9 +1368,14 @@ static int __device_suspend(struct devic End: if (!error) { dev->power.is_suspended = true; - if (dev->power.wakeup_path - && dev->parent && !dev->parent->power.ignore_children) - dev->parent->power.wakeup_path = true; + if (dev->parent) { + if (!dev->parent->power.ignore_children + && dev->power.wakeup_path) + dev->parent->power.wakeup_path = true; + + if (!dev->power.fast_suspend) + dev->parent->power.fast_suspend = false; + } } device_unlock(dev); @@ -1460,7 +1475,7 @@ static int device_prepare(struct device { int (*callback)(struct device *) = NULL; char *info = NULL; - int error = 0; + int ret = 0; if (dev->power.syscore) return 0; @@ -1476,6 +1491,7 @@ static int device_prepare(struct device device_lock(dev); dev->power.wakeup_path = device_may_wakeup(dev); + dev->power.fast_suspend = false; if (dev->pm_domain) { info = "preparing power domain "; @@ -1497,16 +1513,19 @@ static int device_prepare(struct device } if (callback) { - error = callback(dev); - suspend_report_result(callback, error); + ret = callback(dev); + suspend_report_result(callback, ret); } device_unlock(dev); - if (error) + if (ret < 0) { pm_runtime_put(dev); - - return error; + return ret; + } else if (ret > 0) { + dev->power.fast_suspend = true; + } + return 0; } /** @@ -1575,7 +1594,7 @@ EXPORT_SYMBOL_GPL(dpm_suspend_start); void __suspend_report_result(const char *function, void *fn, int ret) { - if (ret) + if (ret < 0) printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret); } EXPORT_SYMBOL_GPL(__suspend_report_result); Index: linux-pm/include/linux/pm.h =================================================================== --- linux-pm.orig/include/linux/pm.h +++ linux-pm/include/linux/pm.h @@ -546,6 +546,7 @@ struct dev_pm_info { bool is_late_suspended:1; bool ignore_children:1; bool early_init:1; /* Owned by the PM core */ + bool fast_suspend:1; /* Owned by the PM core */ spinlock_t lock; #ifdef CONFIG_PM_SLEEP struct list_head entry;