diff options
| author | Florian Echtler <floe@butterbrot.org> | 2015-03-31 06:43:28 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2015-04-08 06:28:56 -0300 |
| commit | c2529908a1905cd8b76bed0a6039975226cb24eb (patch) | |
| tree | e6dba3f1a48f4d54cf060ee77f00a9e623dd6239 /drivers/input/touchscreen/sur40.c | |
| parent | af7f388e7452e1707f862378f38a0372c6c33728 (diff) | |
[media] sur40: fix occasional hard freeze due to buffer queue underrun
This patch fixes a kernel panic which occurs when buf_list is empty. This can
happen occasionally when user space is under heavy load (e.g. due to image
processing on the CPU) and new buffers aren't re-queued fast enough. In that
case, vb2_start_streaming_called can return true, but when the spinlock
is taken and sur40_poll attempts to fetch the next buffer from buf_list, the
list is in fact empty.
This patch needs to be applied on top of the queued one adding V4L2 support
to the sur40 driver.
Signed-off-by: Florian Echtler <floe@butterbrot.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Diffstat (limited to 'drivers/input/touchscreen/sur40.c')
| -rw-r--r-- | drivers/input/touchscreen/sur40.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/sur40.c b/drivers/input/touchscreen/sur40.c index b295e1744ea1..a24eba5ea843 100644 --- a/drivers/input/touchscreen/sur40.c +++ b/drivers/input/touchscreen/sur40.c @@ -380,6 +380,11 @@ static void sur40_process_video(struct sur40_state *sur40) /* get a new buffer from the list */ spin_lock(&sur40->qlock); + if (list_empty(&sur40->buf_list)) { + dev_dbg(sur40->dev, "buffer queue empty\n"); + spin_unlock(&sur40->qlock); + return; + } new_buf = list_entry(sur40->buf_list.next, struct sur40_buffer, list); list_del(&new_buf->list); spin_unlock(&sur40->qlock); |