From 58aca23226a19983571bd3b65167521fc64f5869 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Mar 2008 00:57:22 +0100 Subject: 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 Acked-by: Pavel Machek Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/base/core.c') 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; -- cgit v1.2.3