On Thu, 22 Dec 2011, Javier Martin wrote:
> To properly detect frame loss the driver must keep
> track of a frame_count.
>
> Furthermore, field_count use was erroneous because
> in progressive format this must be incremented twice.
Hm, sorry, why this? I just looked at vivi.c - the version before
videobuf2 conversion - and it seems to only increment the count by one.
>
> Signed-off-by: Javier Martin <javier.martin@xxxxxxxxxxxxxxxxx>
> ---
> drivers/media/video/mx2_camera.c | 5 ++++-
> 1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/media/video/mx2_camera.c b/drivers/media/video/mx2_camera.c
> index ea1f4dc..ca76dd2 100644
> --- a/drivers/media/video/mx2_camera.c
> +++ b/drivers/media/video/mx2_camera.c
> @@ -255,6 +255,7 @@ struct mx2_camera_dev {
> dma_addr_t discard_buffer_dma;
> size_t discard_size;
> struct mx2_fmt_cfg *emma_prp;
> + u32 frame_count;
The rule I usually follow, when choosing variable type is the following:
does it really have to be fixed bit-width? The positive reply is pretty
rare, it comes mostly if (a) the variable is used to store values read
from or written to some (fixed-width) hardware registers, or (b) the
variable belongs to a fixed ABI, that has to be the same on different
(32-bit, 64-bit) systems, like (arguably) ioctl()s, data, transferred over
the network or stored on a medium (filesystems,...). This doesn't seem to
be the case here, so, I would just use an (unsigned) int.
Thanks
Guennadi
> };
>
> /* buffer for one video frame */
> @@ -368,6 +369,7 @@ static int mx2_camera_add_device(struct soc_camera_device *icd)
> writel(pcdev->csicr1, pcdev->base_csi + CSICR1);
>
> pcdev->icd = icd;
> + pcdev->frame_count = 0;
>
> dev_info(icd->parent, "Camera driver attached to camera %d\n",
> icd->devnum);
> @@ -1211,7 +1213,8 @@ static void mx27_camera_frame_done_emma(struct mx2_camera_dev *pcdev,
> list_del(&vb->queue);
> vb->state = state;
> do_gettimeofday(&vb->ts);
> - vb->field_count++;
> + vb->field_count = pcdev->frame_count * 2;
> + pcdev->frame_count++;
>
> wake_up(&vb->done);
> }
> --
> 1.7.0.4
>
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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