On 07/03/2015 03:28 PM, Sakari Ailus wrote:
> Hi Hans,
>
> Hans Verkuil wrote:
>> On 07/03/2015 02:47 PM, Sakari Ailus wrote:
>>> 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
>>
>> It's spelled as requeuing (no e). The verb is 'to queue', but the -ing form
>> is
>> queuing. Check the dictionary: http://dictionary.reference.com/browse/queuing
>
> My dictionary disagrees with yours. :-)
>
> http://dictionary.cambridge.org/dictionary/british/queue?q=queueing
$ git grep -i queueing|wc
655 5660 54709
$ git grep -i queuing|wc
650 5623 55249
That's not helpful either...
On the other hand:
$ git grep -i queuing drivers/media/|wc
19 200 1846
$ git grep -i queueing drivers/media/|wc
2 25 203
Within drivers/media there seems to be a clear preference for queuing :-)
But yes, both spellings are OK, but for me queueing has way too many vowels!
And interestingly, my spellchecker thinks queueing is wrong.
>
>>
>>> 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")
>>> Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com>
>>> Cc: sta...@vger.kernel.org # for v4.1
>>> ---
>>> since v1:
>>>
>>> - Instead of relying on q->start_streaming_called and q->streaming, add a
>>> new buffer state VB2_BUF_STATE_REQUEUEING, as suggested by Hans. The
>>> cobalt driver will need the new flag as it returns the buffer back to the
>>> driver's queue, the rest will continue using VB2_BUF_STATE_QUEUED.
>>>
>>> drivers/media/pci/cobalt/cobalt-irq.c | 2 +-
>>> drivers/media/v4l2-core/videobuf2-core.c | 15 +++++++++++----
>>> include/media/videobuf2-core.h | 2 ++
>>> 3 files changed, 14 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/media/pci/cobalt/cobalt-irq.c
>>> b/drivers/media/pci/cobalt/cobalt-irq.c
>>> index e18f49e..2687cb0 100644
>>> --- a/drivers/media/pci/cobalt/cobalt-irq.c
>>> +++ b/drivers/media/pci/cobalt/cobalt-irq.c
>>> @@ -134,7 +134,7 @@ done:
>>> also know about dropped frames. */
>>> cb->vb.v4l2_buf.sequence = s->sequence++;
>>> vb2_buffer_done(&cb->vb, (skip || s->unstable_frame) ?
>>> - VB2_BUF_STATE_QUEUED : VB2_BUF_STATE_DONE);
>>> + VB2_BUF_STATE_REQUEUEING : VB2_BUF_STATE_DONE);
>>> }
>>>
>>> irqreturn_t cobalt_irq_handler(int irq, void *dev_id)
>>> diff --git a/drivers/media/v4l2-core/videobuf2-core.c
>>> b/drivers/media/v4l2-core/videobuf2-core.c
>>> index 1a096a6..ca8c041 100644
>>> --- a/drivers/media/v4l2-core/videobuf2-core.c
>>> +++ b/drivers/media/v4l2-core/videobuf2-core.c
>>> @@ -1182,7 +1182,8 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum
>>> vb2_buffer_state state)
>>>
>>> if (WARN_ON(state != VB2_BUF_STATE_DONE &&
>>> state != VB2_BUF_STATE_ERROR &&
>>> - state != VB2_BUF_STATE_QUEUED))
>>> + state != VB2_BUF_STATE_QUEUED &&
>>> + state != VB2_BUF_STATE_REQUEUEING))
>>> state = VB2_BUF_STATE_ERROR;
>>>
>>> #ifdef CONFIG_VIDEO_ADV_DEBUG
>>> @@ -1199,15 +1200,21 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum
>>> vb2_buffer_state state)
>>> for (plane = 0; plane < vb->num_planes; ++plane)
>>> call_void_memop(vb, finish, vb->planes[plane].mem_priv);
>>>
>>> - /* Add the buffer to the done buffers list */
>>> spin_lock_irqsave(&q->done_lock, flags);
>>> - vb->state = state;
>>> - if (state != VB2_BUF_STATE_QUEUED)
>>> + if (state == VB2_BUF_STATE_QUEUED ||
>>> + state == VB2_BUF_STATE_REQUEUEING) {
>>> + vb->state = VB2_BUF_STATE_QUEUED;
>>> + } else {
>>> + /* Add the buffer to the done buffers list */
>>> list_add_tail(&vb->done_entry, &q->done_list);
>>> + vb->state = state;
>>> + }
>>> atomic_dec(&q->owned_by_drv_count);
>>> spin_unlock_irqrestore(&q->done_lock, flags);
>>>
>>> if (state == VB2_BUF_STATE_QUEUED) {
>>> + return;
>>> + } else if (state == VB2_BUF_STATE_REQUEUEING) {
>>
>> No 'else' is needed here since the 'if' just returns.
>
> Will fix.
>
Regards,
Hans
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
