| Message ID | 1470684652-16295-10-git-send-email-robert.jarzmik@free.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Robert Jarzmik <robert.jarzmik@free.fr> writes: > Add sequence numbers to completed buffers. > > Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> > --- > drivers/media/platform/soc_camera/pxa_camera.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/media/platform/soc_camera/pxa_camera.c b/drivers/media/platform/soc_camera/pxa_camera.c > index d66443ac1f4d..8a65f126d091 100644 > --- a/drivers/media/platform/soc_camera/pxa_camera.c > +++ b/drivers/media/platform/soc_camera/pxa_camera.c > @@ -401,6 +402,7 @@ static void pxa_camera_start_capture(struct pxa_camera_dev *pcdev) > unsigned long cicr0; > > dev_dbg(pcdev_to_dev(pcdev), "%s\n", __func__); > + pcdev->buf_sequence = 0; I'm not so sure this is the right place to reset the buffer sequence. I've seen no documentation on the rules applicable to this sequence number: - should it be reset if a "start streaming" operation occurs ? - should it be reset if a streams stops by lack of video buffers queued ? - should it be reset in queue_setup() like in other drivers ? Or should it _never_ be reset and only be a monotonic raising number ? Cheers. -- Robert -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/15/2016 03:26 PM, Robert Jarzmik wrote: > Robert Jarzmik <robert.jarzmik@free.fr> writes: > >> Add sequence numbers to completed buffers. >> >> Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> >> --- >> drivers/media/platform/soc_camera/pxa_camera.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/media/platform/soc_camera/pxa_camera.c b/drivers/media/platform/soc_camera/pxa_camera.c >> index d66443ac1f4d..8a65f126d091 100644 >> --- a/drivers/media/platform/soc_camera/pxa_camera.c >> +++ b/drivers/media/platform/soc_camera/pxa_camera.c >> @@ -401,6 +402,7 @@ static void pxa_camera_start_capture(struct pxa_camera_dev *pcdev) >> unsigned long cicr0; >> >> dev_dbg(pcdev_to_dev(pcdev), "%s\n", __func__); >> + pcdev->buf_sequence = 0; > > I'm not so sure this is the right place to reset the buffer sequence. > > I've seen no documentation on the rules applicable to this sequence number: > - should it be reset if a "start streaming" operation occurs ? start_streaming is the recommended place for setting the counter to 0. It's what v4l2-compliance expects. It is not documented since 1) not every driver does this and 2) there may be cases where this behavior is not desired. That said, I have yet to see a driver where zeroing this in start_streaming is not appropriate. Regards, Hans > - should it be reset if a streams stops by lack of video buffers queued ? > - should it be reset in queue_setup() like in other drivers ? > > Or should it _never_ be reset and only be a monotonic raising number ? > > Cheers. > > -- > Robert > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hans Verkuil <hverkuil@xs4all.nl> writes: > On 08/15/2016 03:26 PM, Robert Jarzmik wrote: >> Robert Jarzmik <robert.jarzmik@free.fr> writes: >> I've seen no documentation on the rules applicable to this sequence number: >> - should it be reset if a "start streaming" operation occurs ? > > start_streaming is the recommended place for setting the counter to 0. It's what > v4l2-compliance expects. > > It is not documented since 1) not every driver does this and 2) there may > be cases where this behavior is not desired. > > That said, I have yet to see a driver where zeroing this in start_streaming > is not appropriate. Thanks for the information Hans, I'll modify this patch accordingly. Cheers. -- Robert -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/platform/soc_camera/pxa_camera.c b/drivers/media/platform/soc_camera/pxa_camera.c index d66443ac1f4d..8a65f126d091 100644 --- a/drivers/media/platform/soc_camera/pxa_camera.c +++ b/drivers/media/platform/soc_camera/pxa_camera.c @@ -223,6 +223,7 @@ struct pxa_camera_dev { struct list_head capture; spinlock_t lock; + unsigned int buf_sequence; struct pxa_buffer *active; struct tasklet_struct task_eof; @@ -401,6 +402,7 @@ static void pxa_camera_start_capture(struct pxa_camera_dev *pcdev) unsigned long cicr0; dev_dbg(pcdev_to_dev(pcdev), "%s\n", __func__); + pcdev->buf_sequence = 0; __raw_writel(__raw_readl(pcdev->base + CISR), pcdev->base + CISR); /* Enable End-Of-Frame Interrupt */ cicr0 = __raw_readl(pcdev->base + CICR0) | CICR0_ENB; @@ -425,10 +427,13 @@ static void pxa_camera_wakeup(struct pxa_camera_dev *pcdev, struct pxa_buffer *buf) { struct vb2_buffer *vb = &buf->vbuf.vb2_buf; + struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); /* _init is used to debug races, see comment in pxa_camera_reqbufs() */ list_del_init(&buf->queue); vb->timestamp = ktime_get_ns(); + vbuf->sequence = pcdev->buf_sequence++; + vbuf->field = V4L2_FIELD_NONE; vb2_buffer_done(vb, VB2_BUF_STATE_DONE); dev_dbg(pcdev_to_dev(pcdev), "%s dequeud buffer (buf=0x%p)\n", __func__, buf);
Add sequence numbers to completed buffers. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> --- drivers/media/platform/soc_camera/pxa_camera.c | 5 +++++ 1 file changed, 5 insertions(+)