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authorRafael J. Wysocki <rjw@sisk.pl>2008-03-12 00:57:22 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2008-04-19 19:10:24 -0700
commit58aca23226a19983571bd3b65167521fc64f5869 (patch)
tree1fd3f54ce5f18dc972b77970289a27a4e4a39bee /drivers/base/core.c
parent6bcf19d02a5d7e627fa054f2f10e0a8d830df326 (diff)
PM: Handle device registrations during suspend/resume
Modify the PM core to protect its data structures, specifically the dpm_active list, from being corrupted if a child of the currently suspending device is registered concurrently with its ->suspend() callback. In that case, since the new device (the child) is added to dpm_active after its parent, the PM core will attempt to suspend it after the parent, which is wrong. Introduce a new member of struct dev_pm_info, called 'sleeping', and use it to check if the parent of the device being added to dpm_active has been suspended, in which case the device registration fails. Also, use 'sleeping' for checking if the ordering of devices on dpm_active is correct. Introduce variable 'all_sleeping' that will be set to 'true' once all devices have been suspended and make new device registrations fail until 'all_sleeping' is reset to 'false', in order to avoid having unsuspended devices around while the system is going into a sleep state. Remove pm_sleep_rwsem which is not necessary any more. Special thanks to Alan Stern for discussions and suggestions that lead to the creation of this patch. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/base/core.c')
-rw-r--r--drivers/base/core.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 24198ad01976..79848e6c5db5 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -820,7 +820,11 @@ int device_add(struct device *dev)
error = dpm_sysfs_add(dev);
if (error)
goto PMError;
- device_pm_add(dev);
+ error = device_pm_add(dev);
+ if (error) {
+ dpm_sysfs_remove(dev);
+ goto PMError;
+ }
error = bus_add_device(dev);
if (error)
goto BusError;