On 3/20/19 11:21 AM, Mauro Carvalho Chehab wrote:
> Em Wed, 6 Mar 2019 13:13:21 -0800
> Dafna Hirschfeld <dafna3@xxxxxxxxx> escreveu:
>
>> From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
>>
>> Stateless codecs require the use of the Request API as opposed of it
>> being optional.
>>
>> So add a bit to indicate this and let vb2 check for this.
>>
>> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
>> ---
>> drivers/media/common/videobuf2/videobuf2-core.c | 5 ++++-
>> drivers/media/common/videobuf2/videobuf2-v4l2.c | 6 ++++++
>> include/media/videobuf2-core.h | 3 +++
>> 3 files changed, 13 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>> index 15b6b9c0a2e4..d8cf9d3ec54d 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>> @@ -1518,7 +1518,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
>>
>> if ((req && q->uses_qbuf) ||
>> (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
>> - q->uses_requests)) {
>> + (q->uses_requests || q->requires_requests))) {
>> dprintk(1, "queue in wrong mode (qbuf vs requests)\n");
>> return -EBUSY;
>
> Huh? -EBUSY doesn't seem the right error code to be issued if a driver
> ignores V4L2_BUF_CAP_REQUIRES_REQUESTS.
I agree. See my next comment below.
>
>> }
>> @@ -2247,6 +2247,9 @@ int vb2_core_queue_init(struct vb2_queue *q)
>> WARN_ON(!q->ops->buf_queue))
>> return -EINVAL;
>>
>> + if (WARN_ON(q->requires_requests && !q->supports_requests))
>> + return -EINVAL;
>> +
>> INIT_LIST_HEAD(&q->queued_list);
>> INIT_LIST_HEAD(&q->done_list);
>> spin_lock_init(&q->done_lock);
>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> index d09dee20e421..4dc4855056f1 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> @@ -385,6 +385,10 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
>> dprintk(1, "%s: queue uses requests\n", opname);
>> return -EBUSY;
>> }
>> + if (q->requires_requests) {
>> + dprintk(1, "%s: queue requires requests\n", opname);
>> + return -EACCES;
>
> I also don't think that -EACCES is the right error. This is not a matter of
> wrong permissions. Running the app as root won't make it work.
I believe EPERM is returned if you have the wrong permissions.
EACCES is returned when you are in the wrong mode, e.g. when attempting
to set a read-only control, or read from a write-only control.
So I believe this is indeed the right error code. And I also agree that the
core code above should return EACCES as well in this particular case instead
of EBUSY.
Regards,
Hans
>
>> + }
>> return 0;
>> } else if (!q->supports_requests) {
>> dprintk(1, "%s: queue does not support requests\n", opname);
>> @@ -658,6 +662,8 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
>> #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
>> if (q->supports_requests)
>> *caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
>> + if (q->requires_requests)
>> + *caps |= V4L2_BUF_CAP_REQUIRES_REQUESTS;
>> #endif
>> }
>>
>> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
>> index 910f3d469005..fbf8dbbcbc09 100644
>> --- a/include/media/videobuf2-core.h
>> +++ b/include/media/videobuf2-core.h
>> @@ -484,6 +484,8 @@ struct vb2_buf_ops {
>> * has not been called. This is a vb1 idiom that has been adopted
>> * also by vb2.
>> * @supports_requests: this queue supports the Request API.
>> + * @requires_requests: this queue requires the Request API. If this is set to 1,
>> + * then supports_requests must be set to 1 as well.
>> * @uses_qbuf: qbuf was used directly for this queue. Set to 1 the first
>> * time this is called. Set to 0 when the queue is canceled.
>> * If this is 1, then you cannot queue buffers from a request.
>> @@ -558,6 +560,7 @@ struct vb2_queue {
>> unsigned allow_zero_bytesused:1;
>> unsigned quirk_poll_must_check_waiting_for_buffers:1;
>> unsigned supports_requests:1;
>> + unsigned requires_requests:1;
>> unsigned uses_qbuf:1;
>> unsigned uses_requests:1;
>>
>
>
>
> Thanks,
> Mauro
>
