[media] em28xx: fix deadlock when unplugging and replugging a DVB adapter
This fixes the deadlock that occurs with either multiple PCTV 290e adapters or when a single PCTV 290e adapter is replugged.
For DVB devices, the device lock must now *not* be held when adding/removing either a device or an extension to the respective lists. (Because em28xx_init_dvb() will want to take the lock instead).
Conversely, for Audio-Only devices, the device lock *must* be held when adding/removing either a device or an extension to the respective lists.
Signed-off-by: Chris Rankin <rankincj@yahoo.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/em28xx/em28xx-cards.c b/drivers/media/video/em28xx/em28xx-cards.c
index 7297d90..2e1c121 100644
--- a/drivers/media/video/em28xx/em28xx-cards.c
+++ b/drivers/media/video/em28xx/em28xx-cards.c
@@ -3005,7 +3005,9 @@
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);
@@ -3301,10 +3303,10 @@
em28xx_release_resources(dev);
}
- em28xx_close_extension(dev);
-
mutex_unlock(&dev->lock);
+ em28xx_close_extension(dev);
+
if (!dev->users) {
kfree(dev->alt_max_pkt_size);
kfree(dev);