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/bus.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/bus.c')
| -rw-r--r-- | drivers/base/bus.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 80ce88de56fa..aa27f76d28cd 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -283,18 +283,22 @@ void device_bind_driver(struct device * dev) */ int driver_probe_device(struct device_driver * drv, struct device * dev) { + int error = 0; + if (drv->bus->match && !drv->bus->match(dev, drv)) return -ENODEV; + down(&dev->sem); dev->driver = drv; if (drv->probe) { - int error = drv->probe(dev); + error = drv->probe(dev); if (error) { dev->driver = NULL; + up(&dev->sem); return error; } } - + up(&dev->sem); device_bind_driver(dev); return 0; } @@ -385,7 +389,10 @@ void driver_attach(struct device_driver * drv) void device_release_driver(struct device * dev) { - struct device_driver * drv = dev->driver; + struct device_driver * drv; + + down(&dev->sem); + drv = dev->driver; if (drv) { sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj)); sysfs_remove_link(&dev->kobj, "driver"); @@ -394,6 +401,7 @@ void device_release_driver(struct device * dev) drv->remove(dev); dev->driver = NULL; } + up(&dev->sem); } |