Re: [PATCH v3 2/9] media: vimc: Add get_frame callback

From: Kieran Bingham
Date: Thu Aug 20 2020 - 11:37:07 EST


Hi Kaaira,

On 19/08/2020 19:04, Kaaira Gupta wrote:
> In the process of making vimc compatible for multiple streams, we need
> to create a frame passing process such that two different entities can
> get the frame from a common entity. This isn't possible currently without
> calling process_frame twice for the common entity, as process_frames
> returns the frame which gets passed on.
>
> So, to take care of this, add a get_frame callback to vimc device and
> use it to get the frames for an entity from previous entity instead of
> returning and passing the frames as an argument in process_frame.
>
> Signed-off-by: Kaaira Gupta <kgupta@xxxxxxxxxxxxx>
> ---
> .../media/test-drivers/vimc/vimc-capture.c | 18 +++++++++++++++---
> drivers/media/test-drivers/vimc/vimc-common.h | 7 ++++---
> .../media/test-drivers/vimc/vimc-debayer.c | 19 ++++++++++++++++---
> drivers/media/test-drivers/vimc/vimc-scaler.c | 18 +++++++++++++++---
> drivers/media/test-drivers/vimc/vimc-sensor.c | 11 +++++++++--
> .../media/test-drivers/vimc/vimc-streamer.c | 10 ++++++----
> 6 files changed, 65 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/media/test-drivers/vimc/vimc-capture.c b/drivers/media/test-drivers/vimc/vimc-capture.c
> index c63496b17b9a..a8cbb8e4d5ba 100644
> --- a/drivers/media/test-drivers/vimc/vimc-capture.c
> +++ b/drivers/media/test-drivers/vimc/vimc-capture.c
> @@ -355,12 +355,13 @@ static void vimc_cap_unregister(struct vimc_ent_device *ved)
> video_unregister_device(&vcap->vdev);
> }
>
> -static void *vimc_cap_process_frame(struct vimc_ent_device *ved,
> - const void *frame)
> +static int vimc_cap_process_frame(struct vimc_ent_device *ved)
> {
> struct vimc_cap_device *vcap = container_of(ved, struct vimc_cap_device,
> ved);
> struct vimc_cap_buffer *vimc_buf;
> + struct v4l2_subdev *sd;
> + const void *frame;
> void *vbuf;
>
> spin_lock(&vcap->qlock);
> @@ -370,7 +371,7 @@ static void *vimc_cap_process_frame(struct vimc_ent_device *ved,
> typeof(*vimc_buf), list);
> if (!vimc_buf) {
> spin_unlock(&vcap->qlock);
> - return ERR_PTR(-EAGAIN);
> + return -EAGAIN;
> }
>
> /* Remove this entry from the list */
> @@ -385,12 +386,22 @@ static void *vimc_cap_process_frame(struct vimc_ent_device *ved,
>
> vbuf = vb2_plane_vaddr(&vimc_buf->vb2.vb2_buf, 0);
>
> + sd = media_entity_to_v4l2_subdev(vimc_get_source_entity(ved->ent));
> + ved = v4l2_get_subdevdata(sd);
> + frame = ved->get_frame(ved);

Hrm, this code block is used in several places throughout this patch,
and it aliases the function parameter ved to a new device which isn't
nice. Not a problem as long as it's not used for the original VED after
of course.

But I wonder if we should instead add a helper into vimc-common.c:

struct vimc_ent_device *vimc_get_source_ved(struct vimc_ent_device *ved)
{
struct media_entity *ent;
struct v4l2_subdev *sd;

ent = vimc_get_source_entity(ved->ent);
if (!ent)
return NULL;

sd = media_entity_to_v4l2_subdev(ent);

return v4l2_get_subdevdata(sd);
}

It might not be necessary though, just an idea. If you like it, it can
be a patch on it's own after the vimc_get_source_entity() moving patch.


But it does show that vimc_get_source_entity() can return NULL which
might have to be checked... though perhaps we 'know' it will always be
valid ...

Also, following the links for each entity, for each frame sounds like
quite a lot of work. I wonder if the active source entity should be
cached in each VED ...

That could be done on top anyway...

Overall, this looks like it will work, so with comments addressed how
you wish,

Reviewed-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>


> +
> memcpy(vbuf, frame, vcap->format.sizeimage);
>
> /* Set it as ready */
> vb2_set_plane_payload(&vimc_buf->vb2.vb2_buf, 0,
> vcap->format.sizeimage);
> vb2_buffer_done(&vimc_buf->vb2.vb2_buf, VB2_BUF_STATE_DONE);
> +
> + return 0;
> +}
> +
> +static void *vimc_cap_get_frame(struct vimc_ent_device *ved)
> +{
> return NULL;
> }
>
> @@ -455,6 +466,7 @@ static struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
> vcap->ved.ent = &vcap->vdev.entity;
> vcap->ved.process_frame = vimc_cap_process_frame;
> vcap->ved.vdev_get_format = vimc_cap_get_format;
> + vcap->ved.get_frame = vimc_cap_get_frame;
> vcap->ved.dev = vimc->mdev.dev;
>
> /* Initialize the video_device struct */
> diff --git a/drivers/media/test-drivers/vimc/vimc-common.h b/drivers/media/test-drivers/vimc/vimc-common.h
> index 4c580d854007..287d66edff49 100644
> --- a/drivers/media/test-drivers/vimc/vimc-common.h
> +++ b/drivers/media/test-drivers/vimc/vimc-common.h
> @@ -85,7 +85,8 @@ struct vimc_pix_map {
> *
> * @dev: a pointer of the device struct of the driver
> * @ent: the pointer to struct media_entity for the node
> - * @process_frame: callback send a frame to that node
> + * @get_frame: callback that sends a frame processed by the entity

s/sends a/obtains the/



> + * @process_frame: callback that processes a frame
> * @vdev_get_format: callback that returns the current format a pad, used
> * only when is_media_entity_v4l2_video_device(ent) returns
> * true
> @@ -101,8 +102,8 @@ struct vimc_pix_map {
> struct vimc_ent_device {
> struct device *dev;
> struct media_entity *ent;
> - void * (*process_frame)(struct vimc_ent_device *ved,
> - const void *frame);
> + void * (*get_frame)(struct vimc_ent_device *ved);
> + int (*process_frame)(struct vimc_ent_device *ved);
> void (*vdev_get_format)(struct vimc_ent_device *ved,
> struct v4l2_pix_format *fmt);
> };
> diff --git a/drivers/media/test-drivers/vimc/vimc-debayer.c b/drivers/media/test-drivers/vimc/vimc-debayer.c
> index c3f6fef34f68..f61e6e8899ac 100644
> --- a/drivers/media/test-drivers/vimc/vimc-debayer.c
> +++ b/drivers/media/test-drivers/vimc/vimc-debayer.c
> @@ -491,17 +491,22 @@ static void vimc_deb_calc_rgb_sink(struct vimc_deb_device *vdeb,
> }
> }
>
> -static void *vimc_deb_process_frame(struct vimc_ent_device *ved,
> - const void *sink_frame)
> +static int vimc_deb_process_frame(struct vimc_ent_device *ved)
> {
> struct vimc_deb_device *vdeb = container_of(ved, struct vimc_deb_device,
> ved);
> unsigned int rgb[3];
> unsigned int i, j;
> + struct v4l2_subdev *sd;
> + const void *sink_frame;
>
> /* If the stream in this node is not active, just return */
> if (!vdeb->src_frame)
> - return ERR_PTR(-EINVAL);
> + return -EINVAL;
> +
> + sd = media_entity_to_v4l2_subdev(vimc_get_source_entity(ved->ent));
> + ved = v4l2_get_subdevdata(sd);
> + sink_frame = ved->get_frame(ved);
>
> for (i = 0; i < vdeb->sink_fmt.height; i++)
> for (j = 0; j < vdeb->sink_fmt.width; j++) {
> @@ -509,6 +514,13 @@ static void *vimc_deb_process_frame(struct vimc_ent_device *ved,
> vdeb->set_rgb_src(vdeb, i, j, rgb);
> }
>
> + return 0;
> +}
> +
> +static void *vimc_deb_get_frame(struct vimc_ent_device *ved)
> +{
> + struct vimc_deb_device *vdeb = container_of(ved, struct vimc_deb_device,
> + ved);
> return vdeb->src_frame;
> }
>
> @@ -593,6 +605,7 @@ static struct vimc_ent_device *vimc_deb_add(struct vimc_device *vimc,
> goto err_free_hdl;
>
> vdeb->ved.process_frame = vimc_deb_process_frame;
> + vdeb->ved.get_frame = vimc_deb_get_frame;
> vdeb->ved.dev = vimc->mdev.dev;
> vdeb->mean_win_size = vimc_deb_ctrl_mean_win_size.def;
>
> diff --git a/drivers/media/test-drivers/vimc/vimc-scaler.c b/drivers/media/test-drivers/vimc/vimc-scaler.c
> index 121fa7d62a2e..347f9cd4a168 100644
> --- a/drivers/media/test-drivers/vimc/vimc-scaler.c
> +++ b/drivers/media/test-drivers/vimc/vimc-scaler.c
> @@ -455,18 +455,29 @@ static void vimc_sca_fill_src_frame(const struct vimc_sca_device *const vsca,
> vimc_sca_scale_pix(vsca, i, j, sink_frame);
> }
>
> -static void *vimc_sca_process_frame(struct vimc_ent_device *ved,
> - const void *sink_frame)
> +static int vimc_sca_process_frame(struct vimc_ent_device *ved)
> {
> struct vimc_sca_device *vsca = container_of(ved, struct vimc_sca_device,
> ved);
> + const void *sink_frame;
> + struct v4l2_subdev *sd;
>
> /* If the stream in this node is not active, just return */
> if (!vsca->src_frame)
> - return ERR_PTR(-EINVAL);
> + return -EINVAL;
>
> + sd = media_entity_to_v4l2_subdev(vimc_get_source_entity(ved->ent));
> + ved = v4l2_get_subdevdata(sd);
> + sink_frame = ved->get_frame(ved);
> vimc_sca_fill_src_frame(vsca, sink_frame);
>
> + return 0;
> +};
> +
> +static void *vimc_sca_get_frame(struct vimc_ent_device *ved)
> +{
> + struct vimc_sca_device *vsca = container_of(ved, struct vimc_sca_device,
> + ved);
> return vsca->src_frame;
> };
>
> @@ -505,6 +516,7 @@ static struct vimc_ent_device *vimc_sca_add(struct vimc_device *vimc,
> }
>
> vsca->ved.process_frame = vimc_sca_process_frame;
> + vsca->ved.get_frame = vimc_sca_get_frame;
> vsca->ved.dev = vimc->mdev.dev;
>
> /* Initialize the frame format */
> diff --git a/drivers/media/test-drivers/vimc/vimc-sensor.c b/drivers/media/test-drivers/vimc/vimc-sensor.c
> index ba5db5a150b4..32a2c39de2cd 100644
> --- a/drivers/media/test-drivers/vimc/vimc-sensor.c
> +++ b/drivers/media/test-drivers/vimc/vimc-sensor.c
> @@ -190,8 +190,7 @@ static const struct v4l2_subdev_pad_ops vimc_sen_pad_ops = {
> .set_fmt = vimc_sen_set_fmt,
> };
>
> -static void *vimc_sen_process_frame(struct vimc_ent_device *ved,
> - const void *sink_frame)
> +static int vimc_sen_process_frame(struct vimc_ent_device *ved)
> {
> struct vimc_sen_device *vsen = container_of(ved, struct vimc_sen_device,
> ved);
> @@ -238,6 +237,13 @@ static void *vimc_sen_process_frame(struct vimc_ent_device *ved,
> break;
> }
>
> + return 0;
> +}
> +
> +static void *vimc_sen_get_frame(struct vimc_ent_device *ved)
> +{
> + struct vimc_sen_device *vsen = container_of(ved, struct vimc_sen_device,
> + ved);
> return vsen->frame;
> }
>
> @@ -429,6 +435,7 @@ static struct vimc_ent_device *vimc_sen_add(struct vimc_device *vimc,
> goto err_free_tpg;
>
> vsen->ved.process_frame = vimc_sen_process_frame;
> + vsen->ved.get_frame = vimc_sen_get_frame;
> vsen->ved.dev = vimc->mdev.dev;
>
> /* Initialize the frame format */
> diff --git a/drivers/media/test-drivers/vimc/vimc-streamer.c b/drivers/media/test-drivers/vimc/vimc-streamer.c
> index 4f8384246042..c1644d69686d 100644
> --- a/drivers/media/test-drivers/vimc/vimc-streamer.c
> +++ b/drivers/media/test-drivers/vimc/vimc-streamer.c
> @@ -125,7 +125,8 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
> static int vimc_streamer_thread(void *data)
> {
> struct vimc_stream *stream = data;
> - u8 *frame = NULL;
> + struct vimc_ent_device *ved;
> + int ret;
> int i;
>
> set_freezable();
> @@ -136,9 +137,10 @@ static int vimc_streamer_thread(void *data)
> break;
>
> for (i = stream->pipe_size - 1; i >= 0; i--) {
> - frame = stream->ved_pipeline[i]->process_frame(
> - stream->ved_pipeline[i], frame);
> - if (!frame || IS_ERR(frame))
> + ved = stream->ved_pipeline[i];
> + ret = ved->process_frame(ved);
> +
> + if (ret)
> break;
> }
> //wait for 60hz
>

--
Regards
--
Kieran