diff options
| author | mochel@digitalimplant.org <mochel@digitalimplant.org> | 2005-03-21 21:41:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2005-06-21 02:15:12 +0400 |
| commit | af70316af182f4716cc5eec7e0d27fc731d164bd (patch) | |
| tree | 22fa4732c8270db8fd3f681355cd83e4b8088847 /drivers/base/power/suspend.c | |
| parent | eb51b65005737b777e0709683b061d5f82aefd97 (diff) | |
| download | linux-af70316af182f4716cc5eec7e0d27fc731d164bd.tar.xz | |
[PATCH] Add a semaphore to struct device to synchronize calls to its driver.
This adds a per-device semaphore that is taken before every call from the core to a
driver method. This prevents e.g. simultaneous calls to the ->suspend() or ->resume()
and ->probe() or ->release(), potentially saving a whole lot of headaches.
It also moves us a step closer to removing the bus rwsem, since it protects the fields
in struct device that are modified by the core.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/base/power/suspend.c')
| -rw-r--r-- | drivers/base/power/suspend.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/base/power/suspend.c b/drivers/base/power/suspend.c index 0ec44ef840be..807e13fb205b 100644 --- a/drivers/base/power/suspend.c +++ b/drivers/base/power/suspend.c @@ -39,6 +39,7 @@ int suspend_device(struct device * dev, pm_message_t state) { int error = 0; + down(&dev->sem); if (dev->power.power_state) { dev_dbg(dev, "PM: suspend %d-->%d\n", dev->power.power_state, state); @@ -58,7 +59,7 @@ int suspend_device(struct device * dev, pm_message_t state) dev_dbg(dev, "suspending\n"); error = dev->bus->suspend(dev, state); } - + up(&dev->sem); return error; } |