[media] gspca: Fix locking issues related to suspend/resume
There are two bugs here: first the calls to stop0 (in gspca_suspend) and
gspca_init_transfer (in gspca_resume) need to be called with the usb_lock held.
That's true for the other places they are called and it is what subdrivers
expect. Quite a few will unlock the usb_lock in stop0 while waiting for a
worker thread to finish, and if usb_lock isn't held then that can cause a
kernel oops.
The other problem is that a worker thread needs to detect that it has to
halt due to a suspend. Otherwise it will just go on looping. So add tests
against gspca_dev->frozen in the worker threads that need it.
Hdg, 2 minor changes:
1) The finepix device is ok with stopping reading a frame halfway through,
so add frozen checks in all places where we also check if we're still
streaming
2) Use gspca_dev->dev instead of gspca_dev->present to check for disconnect
in all touched drivers. I plan to do this everywhere in the future, and
most relevant lines in the touched drivers are already modified by this
patch.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/gspca/vicam.c b/drivers/media/video/gspca/vicam.c
index e48ec4d..432d6cd 100644
--- a/drivers/media/video/gspca/vicam.c
+++ b/drivers/media/video/gspca/vicam.c
@@ -225,7 +225,7 @@
goto exit;
}
- while (gspca_dev->present && gspca_dev->streaming) {
+ while (!gspca_dev->frozen && gspca_dev->dev && gspca_dev->streaming) {
ret = vicam_read_frame(gspca_dev, buffer, frame_sz);
if (ret < 0)
break;
@@ -327,7 +327,7 @@
dev->work_thread = NULL;
mutex_lock(&gspca_dev->usb_lock);
- if (gspca_dev->present)
+ if (gspca_dev->dev)
vicam_set_camera_power(gspca_dev, 0);
}