From: Rafael J. Wysocki Date: Tue, 26 Apr 2011 09:33:09 +0000 (+0200) Subject: PM / Wakeup: Fix initialization of wakeup-related device sysfs files X-Git-Tag: v2.6.39-rc6~38^2~1 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=22110faf8c8e980013790e6a5214de32b3303730;p=linux.git PM / Wakeup: Fix initialization of wakeup-related device sysfs files It turns out that some PCI devices are only found to be wakeup-capable during registration, in which case, when device_set_wakeup_capable() is called, device_is_registered() already returns 'true' for the given device, but dpm_sysfs_add() hasn't been called for it yet. This leads to situations in which the device's power.can_wakeup flag is not set as requested because of failing wakeup_sysfs_add() and its wakeup-related sysfs files are not created, although they should be present. This is a post-2.6.38 regression introduced by commit cb8f51bdadb7969139c2e39c2defd4cde98c1 (PM: Do not create wakeup sysfs files for devices that cannot wake up). To work around this problem initialize the device's power.entry field to an empty list head and make device_set_wakeup_capable() check if it is still empty before attempting to add the devices wakeup-related sysfs files with wakeup_sysfs_add(). Namely, if power.entry is still empty at this point, device_pm_add() hasn't been called yet for the device and its wakeup-related files will be created later, so device_set_wakeup_capable() doesn't have to create them. Reported-and-tested-by: Tino Keitel Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman --- diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index fbc5b6e7c591..abe3ab709e87 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -63,6 +63,7 @@ void device_pm_init(struct device *dev) dev->power.wakeup = NULL; spin_lock_init(&dev->power.lock); pm_runtime_init(dev); + INIT_LIST_HEAD(&dev->power.entry); } /** diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index 4573c83df6dd..abbbd33e8d8a 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -258,7 +258,7 @@ void device_set_wakeup_capable(struct device *dev, bool capable) if (!!dev->power.can_wakeup == !!capable) return; - if (device_is_registered(dev)) { + if (device_is_registered(dev) && !list_empty(&dev->power.entry)) { if (capable) { if (wakeup_sysfs_add(dev)) return;