Re: [PATCH v11 07/12] media: mediatek: jpeg: fix decoding resolution change operation

["Kyrie Wu (吴晗)" <Kyrie.Wu@mediatek.com>]

On Tue, 2025-12-16 at 16:40 -0500, Nicolas Dufresne wrote:
> Hi,
> 
> Le mardi 02 décembre 2025 à 17:47 +0800, Kyrie Wu a écrit :
> > 1.add a judgement for src buffer to avoid kernel crash
> > in the stop streaming function;
> > 2.When a resolution changing occurs, it needs to set new
> > resolution parameter immediately and then report this event.
> > Otherwise, if the original software process is maintained,
> > the resolution change event is reported firstly, the CPU is
> > dispatched to the app to process the event, and the driver
> > does not set a new resolution, which will cause parameter errors.
> > 3.After a resolution change occurred, decoding should not continue,
> > needs to wait until new buffers are ready and the state machine
> > changed.
> 
> I mention this in other patchset, very often, 3 bullets means 3
> distinct
> changes. Don't use bullets. Reflow this text, rework this text, there
> is many
> syntax error here.
> 
Thanks. I will rework it.

Kyrie.
> > 
> > Fixes: dedc21500334 ("media: mtk-jpegdec: add jpeg decode worker
> > interface")
> > 
> > Signed-off-by: Kyrie Wu <kyrie.wu@mediatek.com>
> > ---
> >  drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c | 9 +++++++--
> >  1 file changed, 7 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> > b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> > index 5ffaee4dcd19..9233bbfe2d97 100644
> > --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> > +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> > @@ -887,7 +887,8 @@ static void mtk_jpeg_dec_stop_streaming(struct
> > vb2_queue
> > *q)
> >  
> >  		vb = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
> >  		src_buf = mtk_jpeg_vb2_to_srcbuf(&vb->vb2_buf);
> > -		mtk_jpeg_set_queue_data(ctx, &src_buf->dec_param);
> > +		if (!IS_ERR_OR_NULL(src_buf))
> > +			mtk_jpeg_set_queue_data(ctx, &src_buf-
> > >dec_param);
> 
> The lack of vb2_wait_for_all_buffers() might explains this better,
> you might not
> need to do random null checks like this.
> 
> Nicolas
> 
> >  		ctx->state = MTK_JPEG_RUNNING;
> >  	} else if (V4L2_TYPE_IS_OUTPUT(q->type)) {
> >  		ctx->state = MTK_JPEG_INIT;
> > @@ -1749,11 +1750,15 @@ static void mtk_jpegdec_worker(struct
> > work_struct
> > *work)
> >  
> >  	if (mtk_jpeg_check_resolution_change(ctx,
> >  					     &jpeg_src_buf->dec_param)) 
> > {
> > -		mtk_jpeg_queue_src_chg_event(ctx);
> > +		mtk_jpeg_set_queue_data(ctx, &jpeg_src_buf->dec_param);
> >  		ctx->state = MTK_JPEG_SOURCE_CHANGE;
> > +		mtk_jpeg_queue_src_chg_event(ctx);
> >  		goto getbuf_fail;
> >  	}
> >  
> > +	if (ctx->state == MTK_JPEG_SOURCE_CHANGE)
> > +		goto getbuf_fail;
> > +
> >  	mtk_jpegdec_set_hw_param(ctx, hw_id, src_buf, dst_buf);
> >  	ret = pm_runtime_resume_and_get(comp_jpeg[hw_id]->dev);
> >  	if (ret < 0) {