Re: [PATCH v8 2/4] vcodec: mediatek: Add Mediatek JPEG Decoder Driver

[Rick Chang <rick.chang@mediatek.com>]

Hi Ricky,

Thanks for your feedback. We will fix the problem in another patch.

On Mon, 2016-12-12 at 12:34 +0800, Ricky Liang wrote:
> Hi Rick,
> 
> On Wed, Nov 30, 2016 at 11:08 AM, Rick Chang <rick.chang@mediatek.com> wrote:
> > Add v4l2 driver for Mediatek JPEG Decoder
> >
> > Signed-off-by: Rick Chang <rick.chang@mediatek.com>
> > Signed-off-by: Minghsiu Tsai <minghsiu.tsai@mediatek.com>
> 
> <snip...>
> 
> > +static bool mtk_jpeg_check_resolution_change(struct mtk_jpeg_ctx *ctx,
> > +                                            struct mtk_jpeg_dec_param *param)
> > +{
> > +       struct mtk_jpeg_dev *jpeg = ctx->jpeg;
> > +       struct mtk_jpeg_q_data *q_data;
> > +
> > +       q_data = &ctx->out_q;
> > +       if (q_data->w != param->pic_w || q_data->h != param->pic_h) {
> > +               v4l2_dbg(1, debug, &jpeg->v4l2_dev, "Picture size change\n");
> > +               return true;
> > +       }
> > +
> > +       q_data = &ctx->cap_q;
> > +       if (q_data->fmt != mtk_jpeg_find_format(ctx, param->dst_fourcc,
> > +                                               MTK_JPEG_FMT_TYPE_CAPTURE)) {
> > +               v4l2_dbg(1, debug, &jpeg->v4l2_dev, "format change\n");
> > +               return true;
> > +       }
> > +       return false;
> 
> <snip...>
> 
> > +static void mtk_jpeg_device_run(void *priv)
> > +{
> > +       struct mtk_jpeg_ctx *ctx = priv;
> > +       struct mtk_jpeg_dev *jpeg = ctx->jpeg;
> > +       struct vb2_buffer *src_buf, *dst_buf;
> > +       enum vb2_buffer_state buf_state = VB2_BUF_STATE_ERROR;
> > +       unsigned long flags;
> > +       struct mtk_jpeg_src_buf *jpeg_src_buf;
> > +       struct mtk_jpeg_bs bs;
> > +       struct mtk_jpeg_fb fb;
> > +       int i;
> > +
> > +       src_buf = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
> > +       dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
> > +       jpeg_src_buf = mtk_jpeg_vb2_to_srcbuf(src_buf);
> > +
> > +       if (jpeg_src_buf->flags & MTK_JPEG_BUF_FLAGS_LAST_FRAME) {
> > +               for (i = 0; i < dst_buf->num_planes; i++)
> > +                       vb2_set_plane_payload(dst_buf, i, 0);
> > +               buf_state = VB2_BUF_STATE_DONE;
> > +               goto dec_end;
> > +       }
> > +
> > +       if (mtk_jpeg_check_resolution_change(ctx, &jpeg_src_buf->dec_param)) {
> > +               mtk_jpeg_queue_src_chg_event(ctx);
> > +               ctx->state = MTK_JPEG_SOURCE_CHANGE;
> > +               v4l2_m2m_job_finish(jpeg->m2m_dev, ctx->fh.m2m_ctx);
> > +               return;
> > +       }
> 
> This only detects source change if multiple OUPUT buffers are queued.
> It does not catch the source change in the following scenario:
> 
> - OUPUT buffers for jpeg1 enqueued
> - OUTPUT queue STREAMON
> - userspace creates CAPTURE buffers
> - CAPTURE buffers enqueued
> - CAPTURE queue STREAMON
> - decode
> - OUTPUT queue STREAMOFF
> - userspace recreates OUTPUT buffers for jpeg2
> - OUTPUT buffers for jpeg2 enqueued
> - OUTPUT queue STREAMON
> 
> In the above sequence if jpeg2's decoded size is larger than jpeg1 the
> function fails to detect that the existing CAPTURE buffers are not big
> enough to hold the decoded data.
> 
> A possible fix is to pass *dst_buf to
> mtk_jpeg_check_resolution_change(), and check in the function that all
> the dst_buf planes are large enough to hold the decoded data.
> 
> > +
> > +       mtk_jpeg_set_dec_src(ctx, src_buf, &bs);
> > +       if (mtk_jpeg_set_dec_dst(ctx, &jpeg_src_buf->dec_param, dst_buf, &fb))
> > +               goto dec_end;
> > +
> > +       spin_lock_irqsave(&jpeg->hw_lock, flags);
> > +       mtk_jpeg_dec_reset(jpeg->dec_reg_base);
> > +       mtk_jpeg_dec_set_config(jpeg->dec_reg_base,
> > +                               &jpeg_src_buf->dec_param, &bs, &fb);
> > +
> > +       mtk_jpeg_dec_start(jpeg->dec_reg_base);
> > +       spin_unlock_irqrestore(&jpeg->hw_lock, flags);
> > +       return;
> > +
> > +dec_end:
> > +       v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
> > +       v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
> > +       v4l2_m2m_buf_done(to_vb2_v4l2_buffer(src_buf), buf_state);
> > +       v4l2_m2m_buf_done(to_vb2_v4l2_buffer(dst_buf), buf_state);
> > +       v4l2_m2m_job_finish(jpeg->m2m_dev, ctx->fh.m2m_ctx);
> > +}
> 
> <snip...>