Re: [PATCH] hantro: Remove incorrect HEVC SPS validation

[Ezequiel Garcia]

Hi Hans,

On Fri, Jul 08, 2022 at 10:42:43AM +0200, Hans Verkuil wrote:
> 
> 
> On 6/30/22 07:02, Sebastian Fricke wrote:
> > Hey Ezequiel,
> > 
> > On 29.06.2022 16:56, Ezequiel Garcia wrote:
> >> Currently, the driver tries to validat the HEVC SPS
> > 
> > s/validat/validate/
> > 
> >> against the CAPTURE queue format (i.e. the decoded format).
> >> This is not correct, because typically the SPS control is set
> >> before the CAPTURE queue is negotiated.
> >>
> >> In addition to this, a format validation in hantro_hevc_dec_prepare_run()
> >> is also suboptimal, because hantro_hevc_dec_prepare_run() runs in the context
> >> of v4l2_m2m_ops.device_run, as part of a decoding job.
> >>
> >> Format and control validations should happen before decoding starts,
> >> in the context of ioctls such as S_CTRL, S_FMT, or STREAMON.
> >>
> >> Remove the validation for now.
> > 
> > Couldn't we add a small wrapper around STREAMON to perform that
> > validation? I feel like "remove the validation for now", seems like a
> > vague statement.
> 
> I agree. Basically two things happen in this patch: two sanity checks
> for the SPS control are moved to try_ctrl, and that part looks good.
> 
> So that can be a separate patch.
> 
> The second part is the removal of the format+control validation, but it
> is not clear why removing it altogether is wrong. Shouldn't it still be
> done somewhere? And if not, why not?
> 

Sorry for the delayed reply. After giving this format+control validation
more thought, I believe the V4L2 API provides a natural way of handling.

When the format is negotiated in TRY_FMT, the control needs to be used
to offer a valid resolution.

The driver is capable of negotiating the resolution of the stream
using the control information, instead of failing.

I'll send a v2 with a new proposal.

Thanks,
Ezequiel

> Regards,
> 
> 	Hans
> 
> > 
> > Greetings,
> > Sebastian
> > 
> >>
> >> Fixes: 135ad96cb4d6b ("media: hantro: Be more accurate on pixel formats step_width constraints")
> >> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>
> >> ---
> >> drivers/staging/media/hantro/hantro_drv.c  | 12 ++++-----
> >> drivers/staging/media/hantro/hantro_hevc.c | 30 ----------------------
> >> drivers/staging/media/hantro/hantro_hw.h   |  1 -
> >> 3 files changed, 6 insertions(+), 37 deletions(-)
> >>
> >> diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
> >> index afddf7ac0731..2387ca85ab54 100644
> >> --- a/drivers/staging/media/hantro/hantro_drv.c
> >> +++ b/drivers/staging/media/hantro/hantro_drv.c
> >> @@ -253,11 +253,6 @@ queue_init(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq)
> >>
> >> static int hantro_try_ctrl(struct v4l2_ctrl *ctrl)
> >> {
> >> -    struct hantro_ctx *ctx;
> >> -
> >> -    ctx = container_of(ctrl->handler,
> >> -               struct hantro_ctx, ctrl_handler);
> >> -
> >>     if (ctrl->id == V4L2_CID_STATELESS_H264_SPS) {
> >>         const struct v4l2_ctrl_h264_sps *sps = ctrl->p_new.p_h264_sps;
> >>
> >> @@ -273,7 +268,12 @@ static int hantro_try_ctrl(struct v4l2_ctrl *ctrl)
> >>     } else if (ctrl->id == V4L2_CID_MPEG_VIDEO_HEVC_SPS) {
> >>         const struct v4l2_ctrl_hevc_sps *sps = ctrl->p_new.p_hevc_sps;
> >>
> >> -        return hantro_hevc_validate_sps(ctx, sps);
> >> +        if (sps->bit_depth_luma_minus8 != sps->bit_depth_chroma_minus8)
> >> +            /* Luma and chroma bit depth mismatch */
> >> +            return -EINVAL;
> >> +        if (sps->bit_depth_luma_minus8 != 0)
> >> +            /* Only 8-bit is supported */
> >> +            return -EINVAL;
> >>     } else if (ctrl->id == V4L2_CID_STATELESS_VP9_FRAME) {
> >>         const struct v4l2_ctrl_vp9_frame *dec_params = ctrl->p_new.p_vp9_frame;
> >>
> >> diff --git a/drivers/staging/media/hantro/hantro_hevc.c b/drivers/staging/media/hantro/hantro_hevc.c
> >> index bd924896e409..f86c98e19177 100644
> >> --- a/drivers/staging/media/hantro/hantro_hevc.c
> >> +++ b/drivers/staging/media/hantro/hantro_hevc.c
> >> @@ -154,32 +154,6 @@ static int tile_buffer_reallocate(struct hantro_ctx *ctx)
> >>     return -ENOMEM;
> >> }
> >>
> >> -int hantro_hevc_validate_sps(struct hantro_ctx *ctx, const struct v4l2_ctrl_hevc_sps *sps)
> >> -{
> >> -    if (sps->bit_depth_luma_minus8 != sps->bit_depth_chroma_minus8)
> >> -        /* Luma and chroma bit depth mismatch */
> >> -        return -EINVAL;
> >> -    if (sps->bit_depth_luma_minus8 != 0)
> >> -        /* Only 8-bit is supported */
> >> -        return -EINVAL;
> >> -
> >> -    /*
> >> -     * for tile pixel format check if the width and height match
> >> -     * hardware constraints
> >> -     */
> >> -    if (ctx->vpu_dst_fmt->fourcc == V4L2_PIX_FMT_NV12_4L4) {
> >> -        if (ctx->dst_fmt.width !=
> >> -            ALIGN(sps->pic_width_in_luma_samples, ctx->vpu_dst_fmt->frmsize.step_width))
> >> -            return -EINVAL;
> >> -
> >> -        if (ctx->dst_fmt.height !=
> >> -            ALIGN(sps->pic_height_in_luma_samples, ctx->vpu_dst_fmt->frmsize.step_height))
> >> -            return -EINVAL;
> >> -    }
> >> -
> >> -    return 0;
> >> -}
> >> -
> >> int hantro_hevc_dec_prepare_run(struct hantro_ctx *ctx)
> >> {
> >>     struct hantro_hevc_dec_hw_ctx *hevc_ctx = &ctx->hevc_dec;
> >> @@ -203,10 +177,6 @@ int hantro_hevc_dec_prepare_run(struct hantro_ctx *ctx)
> >>     if (WARN_ON(!ctrls->sps))
> >>         return -EINVAL;
> >>
> >> -    ret = hantro_hevc_validate_sps(ctx, ctrls->sps);
> >> -    if (ret)
> >> -        return ret;
> >> -
> >>     ctrls->pps =
> >>         hantro_get_ctrl(ctx, V4L2_CID_MPEG_VIDEO_HEVC_PPS);
> >>     if (WARN_ON(!ctrls->pps))
> >> diff --git a/drivers/staging/media/hantro/hantro_hw.h b/drivers/staging/media/hantro/hantro_hw.h
> >> index a2e0f0836281..5edff0f0be20 100644
> >> --- a/drivers/staging/media/hantro/hantro_hw.h
> >> +++ b/drivers/staging/media/hantro/hantro_hw.h
> >> @@ -359,7 +359,6 @@ int hantro_hevc_dec_prepare_run(struct hantro_ctx *ctx);
> >> void hantro_hevc_ref_init(struct hantro_ctx *ctx);
> >> dma_addr_t hantro_hevc_get_ref_buf(struct hantro_ctx *ctx, int poc);
> >> int hantro_hevc_add_ref_buf(struct hantro_ctx *ctx, int poc, dma_addr_t addr);
> >> -int hantro_hevc_validate_sps(struct hantro_ctx *ctx, const struct v4l2_ctrl_hevc_sps *sps);
> >>
> >>
> >> static inline unsigned short hantro_vp9_num_sbs(unsigned short dimension)
> >> -- 
> >> 2.31.1
> >>