Re: [RFC PATCH v3 05/11] [media] vimc: common: Add vimc_link_validate

Helen Koike
2017-06-12T17:21:18Z

Hi Hans,

Thanks for your review, just a question below

On 2017-06-12 06:50 AM, Hans Verkuil wrote:
> On 06/03/2017 04:58 AM, Helen Koike wrote:
>> All links will be checked in the same way. Adding a helper function for
>> that
>>
>> Signed-off-by: Helen Koike <helen.koike@collabora.com>
>>
>> ---
>>
>> Changes in v3:
>> [media] vimc: common: Add vimc_link_validate
>> - this is a new patch in the series
>>
>> Changes in v2: None
>>
>>
>> ---
>> drivers/media/platform/vimc/vimc-capture.c | 78 +++---------------
>> drivers/media/platform/vimc/vimc-common.c | 124
>> ++++++++++++++++++++++++++++-
>> drivers/media/platform/vimc/vimc-common.h | 14 ++++
>> 3 files changed, 148 insertions(+), 68 deletions(-)
>>
>> diff --git a/drivers/media/platform/vimc/vimc-capture.c
>> b/drivers/media/platform/vimc/vimc-capture.c
>> index 93f6a09..5bdecd1 100644
>> --- a/drivers/media/platform/vimc/vimc-capture.c
>> +++ b/drivers/media/platform/vimc/vimc-capture.c
>> @@ -64,6 +64,15 @@ static int vimc_cap_querycap(struct file *file,
>> void *priv,
>> return 0;
>> }
>> +static void vimc_cap_get_format(struct vimc_ent_device *ved,
>> + struct v4l2_pix_format *fmt)
>> +{
>> + struct vimc_cap_device *vcap = container_of(ved, struct
>> vimc_cap_device,
>> + ved);
>> +
>> + *fmt = vcap->format;
>> +}
>> +
>> static int vimc_cap_fmt_vid_cap(struct file *file, void *priv,
>> struct v4l2_format *f)
>> {
>> @@ -231,74 +240,8 @@ static const struct vb2_ops vimc_cap_qops = {
>> .wait_finish = vb2_ops_wait_finish,
>> };
>> -/*
>> - * NOTE: this function is a copy of v4l2_subdev_link_validate_get_format
>> - * maybe the v4l2 function should be public
>> - */
>> -static int vimc_cap_v4l2_subdev_link_validate_get_format(struct
>> media_pad *pad,
>> - struct v4l2_subdev_format *fmt)
>> -{
>> - struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(pad->entity);
>> -
>> - fmt->which = V4L2_SUBDEV_FORMAT_ACTIVE;
>> - fmt->pad = pad->index;
>> -
>> - return v4l2_subdev_call(sd, pad, get_fmt, NULL, fmt);
>> -}
>> -
>> -static int vimc_cap_link_validate(struct media_link *link)
>> -{
>> - struct v4l2_subdev_format source_fmt;
>> - const struct vimc_pix_map *vpix;
>> - struct vimc_cap_device *vcap = container_of(link->sink->entity,
>> - struct vimc_cap_device,
>> - vdev.entity);
>> - struct v4l2_pix_format *sink_fmt = &vcap->format;
>> - int ret;
>> -
>> - /*
>> - * if it is a raw node from vimc-core, ignore the link for now
>> - * TODO: remove this when there are no more raw nodes in the
>> - * core and return error instead
>> - */
>> - if (link->source->entity->obj_type == MEDIA_ENTITY_TYPE_BASE)
>> - return 0;
>> -
>> - /* Get the the format of the subdev */
>> - ret = vimc_cap_v4l2_subdev_link_validate_get_format(link->source,
>> - &source_fmt);
>> - if (ret)
>> - return ret;
>> -
>> - dev_dbg(vcap->vdev.v4l2_dev->dev,
>> - "%s: link validate formats src:%dx%d %d sink:%dx%d %d\n",
>> - vcap->vdev.name,
>> - source_fmt.format.width, source_fmt.format.height,
>> - source_fmt.format.code,
>> - sink_fmt->width, sink_fmt->height,
>> - sink_fmt->pixelformat);
>> -
>> - /* The width, height and code must match. */
>> - vpix = vimc_pix_map_by_pixelformat(sink_fmt->pixelformat);
>> - if (source_fmt.format.width != sink_fmt->width
>> - || source_fmt.format.height != sink_fmt->height
>> - || vpix->code != source_fmt.format.code)
>> - return -EPIPE;
>> -
>> - /*
>> - * The field order must match, or the sink field order must be NONE
>> - * to support interlaced hardware connected to bridges that support
>> - * progressive formats only.
>> - */
>> - if (source_fmt.format.field != sink_fmt->field &&
>> - sink_fmt->field != V4L2_FIELD_NONE)
>> - return -EPIPE;
>> -
>> - return 0;
>> -}
>> -
>> static const struct media_entity_operations vimc_cap_mops = {
>> - .link_validate = vimc_cap_link_validate,
>> + .link_validate = vimc_link_validate,
>> };
>> static void vimc_cap_destroy(struct vimc_ent_device *ved)
>> @@ -434,6 +377,7 @@ struct vimc_ent_device *vimc_cap_create(struct
>> v4l2_device *v4l2_dev,
>> vcap->ved.destroy = vimc_cap_destroy;
>> vcap->ved.ent = &vcap->vdev.entity;
>> vcap->ved.process_frame = vimc_cap_process_frame;
>> + vcap->ved.vdev_get_format = vimc_cap_get_format;
>> /* Initialize the video_device struct */
>> vdev = &vcap->vdev;
>> diff --git a/drivers/media/platform/vimc/vimc-common.c
>> b/drivers/media/platform/vimc/vimc-common.c
>> index f809a9d..83d4251 100644
>> --- a/drivers/media/platform/vimc/vimc-common.c
>> +++ b/drivers/media/platform/vimc/vimc-common.c
>> @@ -252,8 +252,130 @@ int vimc_pipeline_s_stream(struct media_entity
>> *ent, int enable)
>> return 0;
>> }
>> +static void vimc_fmt_pix_to_mbus(struct v4l2_mbus_framefmt *mfmt,
>> + struct v4l2_pix_format *pfmt)
>> +{
>> + const struct vimc_pix_map *vpix =
>> + vimc_pix_map_by_pixelformat(pfmt->pixelformat);
>> +
>> + mfmt->width = pfmt->width;
>> + mfmt->height = pfmt->height;
>> + mfmt->code = vpix->code;
>> + mfmt->field = pfmt->field;
>> + mfmt->colorspace = pfmt->colorspace;
>> + mfmt->ycbcr_enc = pfmt->ycbcr_enc;
>> + mfmt->quantization = pfmt->quantization;
>> + mfmt->xfer_func = pfmt->xfer_func;
>
> You can use v4l2_fill_mbus_format() here.
>
>> +}
>> +
>> +static int vimc_get_mbus_format(struct media_pad *pad,
>> + struct v4l2_subdev_format *fmt)
>> +{
>> + if (is_media_entity_v4l2_subdev(pad->entity)) {
>> + struct v4l2_subdev *sd =
>> + media_entity_to_v4l2_subdev(pad->entity);
>> + int ret;
>> +
>> + fmt->which = V4L2_SUBDEV_FORMAT_ACTIVE;
>> + fmt->pad = pad->index;
>> +
>> + ret = v4l2_subdev_call(sd, pad, get_fmt, NULL, fmt);
>> + if (ret)
>> + return ret;
>> +
>> + } else if (is_media_entity_v4l2_video_device(pad->entity)) {
>> + struct video_device *vdev = container_of(pad->entity,
>> + struct video_device,
>> + entity);
>> + struct vimc_ent_device *ved = video_get_drvdata(vdev);
>> + struct v4l2_pix_format vdev_fmt;
>> +
>> + if (!ved->vdev_get_format)
>> + return -ENOIOCTLCMD;
>> +
>> + ved->vdev_get_format(ved, &vdev_fmt);
>> + vimc_fmt_pix_to_mbus(&fmt->format, &vdev_fmt);
>> + } else {
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +int vimc_link_validate(struct media_link *link)
>> +{
>> + struct v4l2_subdev_format source_fmt, sink_fmt;
>> + int ret;
>> +
>> + /*
>> + * if it is a raw node from vimc-core, ignore the link for now
>> + * TODO: remove this when there are no more raw nodes in the
>> + * core and return error instead
>> + */
>> + if (link->source->entity->obj_type == MEDIA_ENTITY_TYPE_BASE)
>> + return 0;
>> +
>> + ret = vimc_get_mbus_format(link->source, &source_fmt);
>> + if (ret)
>> + return ret;
>> +
>> + ret = vimc_get_mbus_format(link->sink, &sink_fmt);
>> + if (ret)
>> + return ret;
>> +
>> + pr_info("vimc link validate: "
>> + "%s:src:%dx%d (0x%x, %d, %d, %d, %d) "
>> + "%s:snk:%dx%d (0x%x, %d, %d, %d, %d)\n",
>> + /* src */
>> + link->source->entity->name,
>> + source_fmt.format.width, source_fmt.format.height,
>> + source_fmt.format.code, source_fmt.format.colorspace,
>> + source_fmt.format.quantization, source_fmt.format.xfer_func,
>> + source_fmt.format.ycbcr_enc,
>> + /* sink */
>> + link->sink->entity->name,
>> + sink_fmt.format.width, sink_fmt.format.height,
>> + sink_fmt.format.code, sink_fmt.format.colorspace,
>> + sink_fmt.format.quantization, sink_fmt.format.xfer_func,
>> + sink_fmt.format.ycbcr_enc);
>> +
>> + /* The width, height, code and colorspace must match. */
>> + if (source_fmt.format.width != sink_fmt.format.width
>> + || source_fmt.format.height != sink_fmt.format.height
>> + || source_fmt.format.code != sink_fmt.format.code
>> + || source_fmt.format.colorspace != sink_fmt.format.colorspace)
>
> Source and/or Sink may be COLORSPACE_DEFAULT. If that's the case, then
> you should skip comparing ycbcr_enc, quantization or xfer_func. If
> colorspace
> is DEFAULT, then that implies that the other fields are DEFAULT as well.
> Nothing
> else makes sense in that case.

I thought that the colorspace couldn't be COLORSPACE_DEFAULT, in the
documentation it is written "The default colorspace. This can be used by
applications to let the driver fill in the colorspace.", so the
colorspace is always set to something different from default no ?
I thought that the COLORSPACE_DEFAULT was only used by the userspace in
VIDIOC_{SUBDEV}_S_FMT so say "driver, use wherever colorspace you want",
but if usespace calls VIDIOC_{SUBDEV}_G_FMT, it would return which exact
colorspace the driver is using, no?

>
>> + return -EPIPE;
>> +
>> + /* Colorimetry must match if they are not set to DEFAULT */
>> + if (source_fmt.format.ycbcr_enc != V4L2_YCBCR_ENC_DEFAULT
>> + && sink_fmt.format.ycbcr_enc != V4L2_YCBCR_ENC_DEFAULT
>> + && source_fmt.format.ycbcr_enc != sink_fmt.format.ycbcr_enc)
>> + return -EPIPE;
>> +
>> + if (source_fmt.format.quantization != V4L2_QUANTIZATION_DEFAULT
>> + && sink_fmt.format.quantization != V4L2_QUANTIZATION_DEFAULT
>> + && source_fmt.format.quantization !=
>> sink_fmt.format.quantization)
>> + return -EPIPE;
>> +
>> + if (source_fmt.format.xfer_func != V4L2_XFER_FUNC_DEFAULT
>> + && sink_fmt.format.xfer_func != V4L2_XFER_FUNC_DEFAULT
>> + && source_fmt.format.xfer_func != sink_fmt.format.xfer_func)
>> + return -EPIPE;
>> +
>> + /* The field order must match, or the sink field order must be NONE
>> + * to support interlaced hardware connected to bridges that support
>> + * progressive formats only.
>> + */
>> + if (source_fmt.format.field != sink_fmt.format.field &&
>> + sink_fmt.format.field != V4L2_FIELD_NONE)
>> + return -EPIPE;
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL(vimc_link_validate);
>> +
>> static const struct media_entity_operations vimc_ent_sd_mops = {
>> - .link_validate = v4l2_subdev_link_validate,
>> + .link_validate = vimc_link_validate,
>> };
>> int vimc_ent_sd_register(struct vimc_ent_device *ved,
>> diff --git a/drivers/media/platform/vimc/vimc-common.h
>> b/drivers/media/platform/vimc/vimc-common.h
>> index 73e7e94..60ebde2 100644
>> --- a/drivers/media/platform/vimc/vimc-common.h
>> +++ b/drivers/media/platform/vimc/vimc-common.h
>> @@ -45,6 +45,9 @@ struct vimc_pix_map {
>> * @pads: the list of pads of the node
>> * @destroy: callback to destroy the node
>> * @process_frame: callback send a frame to that node
>> + * @vdev_get_format: callback that returns the current format a
>> pad, used
>> + * only when is_media_entity_v4l2_video_device(ent) returns
>> + * true
>> *
>> * Each node of the topology must create a vimc_ent_device struct.
>> Depending on
>> * the node it will be of an instance of v4l2_subdev or video_device
>> struct
>> @@ -60,6 +63,8 @@ struct vimc_ent_device {
>> void (*destroy)(struct vimc_ent_device *);
>> void (*process_frame)(struct vimc_ent_device *ved,
>> struct media_pad *sink, const void *frame);
>> + void (*vdev_get_format)(struct vimc_ent_device *ved,
>> + struct v4l2_pix_format *fmt);
>> };
>> /**
>> @@ -160,4 +165,13 @@ int vimc_ent_sd_register(struct vimc_ent_device
>> *ved,
>> void vimc_ent_sd_unregister(struct vimc_ent_device *ved,
>> struct v4l2_subdev *sd);
>> +/**
>> + * vimc_link_validate - validates a media link
>> + *
>> + * @link: pointer to &struct media_link
>> + *
>> + * This function calls validates if a media link is valid for streaming.
>> + */
>> +int vimc_link_validate(struct media_link *link);
>> +
>> #endif
>>
>
> Regards,
>
> Hans

Thanks,
Helen