Commit 778f2950 authored Sep 25, 2011 by Chris Rankin Committed by Mauro Carvalho Chehab Sep 25, 2011

[media] em28xx: replug locking cleanup

Simplifies the locking by moving the em28xx_init_extension() call until
em28xx_usb_probe() has finished with the dev->lock mutex. It therefore
makes the second and subsequent "plugging" events logically identical to
the first "plugging" event when the em28xx-dvb and em28xx-alsa modules
must be loaded (i.e. registered).

Basically, em28xx_usb_probe() requests that em28xx-dvb be loaded and
also triggers udev to initialise the V4L2 devices. These two events are
serialised by the dev->lock mutex but the order that they happen in is
undefined. But this has always been the case anyway.

Signed-off-by: Chris Rankin <rankincj@yahoo.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

parent f055815f

drivers/media/video/em28xx/em28xx-cards.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -3005,10 +3005,6 @@ static int em28xx_init_dev(struct em28xx *devhandle, struct usb_device udev,
		goto fail;
		}

		mutex_unlock(&dev->lock);
		em28xx_init_extension(dev);
		mutex_lock(&dev->lock);

		/* Save some power by putting tuner to sleep */
		v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_power, 0);

		@@ -3243,6 +3239,13 @@ static int em28xx_usb_probe(struct usb_interface *interface,
		*/
		mutex_unlock(&dev->lock);

		/*
		* These extensions can be modules. If the modules are already
		* loaded then we can initialise the device now, otherwise we
		* will initialise it when the modules load instead.
		*/
		em28xx_init_extension(dev);

		return 0;

		err: