diff options
| author | mochel@digitalimplant.org <mochel@digitalimplant.org> | 2005-03-21 10:41:04 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2005-06-20 15:15:12 -0700 |
| commit | af70316af182f4716cc5eec7e0d27fc731d164bd (patch) | |
| tree | 22fa4732c8270db8fd3f681355cd83e4b8088847 /drivers/base/power/resume.c | |
| parent | eb51b65005737b777e0709683b061d5f82aefd97 (diff) | |
[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/resume.c')
| -rw-r--r-- | drivers/base/power/resume.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/base/power/resume.c b/drivers/base/power/resume.c index 26468971ef5..bdd96b03b88 100644 --- a/drivers/base/power/resume.c +++ b/drivers/base/power/resume.c @@ -22,6 +22,9 @@ extern int sysdev_resume(void); int resume_device(struct device * dev) { + int error = 0; + + down(&dev->sem); if (dev->power.pm_parent && dev->power.pm_parent->power.power_state) { dev_err(dev, "PM: resume from %d, parent %s still %d\n", @@ -31,9 +34,10 @@ int resume_device(struct device * dev) } if (dev->bus && dev->bus->resume) { dev_dbg(dev,"resuming\n"); - return dev->bus->resume(dev); + error = dev->bus->resume(dev); } - return 0; + up(&dev->sem); + return error; } |