Moikka!
On 07/31/2015 05:43 PM, Sakari Ailus wrote:
Terve,
On Wed, Jul 29, 2015 at 06:29:05PM +0300, Antti Palosaari wrote:
commit ce0eff016f7272faa6dc6eec722b1ca1970ff9aa
[media] vb2: allow requeuing buffers while streaming
That commit causes buf_queue() called on infinity loop when
start_streaming() returns error. On that case resources are eaten
quickly and machine crashes.
Cc: Hans Verkuil <hverkuil@xxxxxxxxx>
Signed-off-by: Antti Palosaari <crope@xxxxxx>
Fixed by this patch in media-fixes:
commit 6d058c5643e16779ae4c001d2e893c140940e48f
Author: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Date: Fri Jul 3 04:37:07 2015 -0300
[media] vb2: Only requeue buffers immediately once streaming is started
Buffers can be returned back to videobuf2 in driver's streamon handler. In
this case vb2_buffer_done() with buffer state VB2_BUF_STATE_QUEUED will
cause the driver's buf_queue vb2 operation to be called, queueing the same
buffer again only to be returned to videobuf2 using vb2_buffer_done() and so
on.
Add a new buffer state VB2_BUF_STATE_REQUEUEING which, when used as the
state argument to vb2_buffer_done(), will result in buffers queued to the
driver. Using VB2_BUF_STATE_QUEUED will leave the buffer to videobuf2, as it
was before "[media] vb2: allow requeuing buffers while streaming".
Fixes: ce0eff016f72 ("[media] vb2: allow requeuing buffers while streaming")
[mchehab@xxxxxxxxxxxxxxx: fix warning: enumeration value 'VB2_BUF_STATE_REQUEUEING' not handled in switch]
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # for v4.1
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
I wonder why this fix is not included to media master yet, but only
fixes... It is not first time such happens. I wasted a lot of time when
I tried implement receiver / transmitter blocking to hackrf driver
start_streaming and it crashes machine always, lets say 15 times, until
I started suspect issue might be somewhere else than driver.
Anyhow, you could crash machine easily with that bug using vivid driver
error injection option
v4l2-ctl -d /dev/video0 -c inject_vidioc_streamon_error=1
regards
Antti
--
http://palosaari.fi/
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