driver core: Add a wrapper around __device_release_driver()

Add an internal wrapper around __device_release_driver() that will
acquire device locks and do the necessary checks before calling it.

The next patch will make use of it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Rafael J. Wysocki 2016-10-10 14:37:56 +02:00 committed by Greg Kroah-Hartman
parent 7f847dd317
commit 4bdb35506b

View File

@ -811,6 +811,22 @@ static void __device_release_driver(struct device *dev)
}
}
static void device_release_driver_internal(struct device *dev,
struct device_driver *drv,
struct device *parent)
{
if (parent)
device_lock(parent);
device_lock(dev);
if (!drv || drv == dev->driver)
__device_release_driver(dev);
device_unlock(dev);
if (parent)
device_unlock(parent);
}
/**
* device_release_driver - manually detach device from driver.
* @dev: device.
@ -825,9 +841,7 @@ void device_release_driver(struct device *dev)
* within their ->remove callback for the same device, they
* will deadlock right here.
*/
device_lock(dev);
__device_release_driver(dev);
device_unlock(dev);
device_release_driver_internal(dev, NULL, NULL);
}
EXPORT_SYMBOL_GPL(device_release_driver);
@ -852,15 +866,7 @@ void driver_detach(struct device_driver *drv)
dev = dev_prv->device;
get_device(dev);
spin_unlock(&drv->p->klist_devices.k_lock);
if (dev->parent) /* Needed for USB */
device_lock(dev->parent);
device_lock(dev);
if (dev->driver == drv)
__device_release_driver(dev);
device_unlock(dev);
if (dev->parent)
device_unlock(dev->parent);
device_release_driver_internal(dev, drv, dev->parent);
put_device(dev);
}
}