atomisp_release() was taking pipe->vb_queue_mutex + isp->mutex at the
same time. But if the /dev/video# node is closed while still streaming
then vb2_queue_release() will call atomisp_stop_streaming() which takes
isp->mutex itself, leading to a deadlock.
To fix this only take isp->mutex after cleaning up the v4l2_fh /
the vb2_queue. While at it switch to vb2_fop_release() which will take
pipe->vb_queue_mutex for us, which also resolves a FIXME comment.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
.../staging/media/atomisp/pci/atomisp_fops.c | 21 +++++--------------
1 file changed, 5 insertions(+), 16 deletions(-)
diff --git a/drivers/staging/media/atomisp/pci/atomisp_fops.c b/drivers/staging/media/atomisp/pci/atomisp_fops.c
index 21ca276831ce..8cff26d42b82 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_fops.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_fops.c
@@ -861,23 +861,14 @@ static int atomisp_release(struct file *file)
v4l2_fh_init(&fh.vfh, vdev);
- mutex_lock(&pipe->vb_queue_mutex);
- mutex_lock(&isp->mutex);
-
dev_dbg(isp->dev, "release device %s\n", vdev->name);
asd->subdev.devnode = vdev;
- /*
- * FIXME This if is copied from _vb2_fop_release, this cannot use that
- * because that calls v4l2_fh_release() earlier then this function.
- * Maybe we can release the fh earlier though, it does not look like
- * anything needs it after this.
- */
- if (file->private_data == vdev->queue->owner) {
- vb2_queue_release(vdev->queue);
- vdev->queue->owner = NULL;
- }
+ /* Note file must not be used after this! */
+ vb2_fop_release(file);
+
+ mutex_lock(&isp->mutex);
pipe->users--;
if (pipe->users)
@@ -940,9 +931,7 @@ static int atomisp_release(struct file *file)
V4L2_SEL_TGT_COMPOSE, 0,
&clear_compose);
mutex_unlock(&isp->mutex);
- mutex_unlock(&pipe->vb_queue_mutex);
-
- return v4l2_fh_release(file);
+ return 0;
}
const struct v4l2_file_operations atomisp_fops = {
--
2.38.1
