[EXT] Re: [PATCH] media: amphion: return error if format is unsupported by vpu

[Nicolas Dufresne]

Le vendredi 20 mai 2022 à 01:25 +0000, Ming Qian a écrit :
> > From: Nicolas Dufresne [mailto:nicolas at ndufresne.ca]
> > Sent: Friday, May 20, 2022 2:13 AM
> > To: Ming Qian <ming.qian at nxp.com>; mchehab at kernel.org;
> > hverkuil-cisco at xs4all.nl
> > Cc: shawnguo at kernel.org; robh+dt at kernel.org; s.hauer at pengutronix.de;
> > kernel at pengutronix.de; festevam at gmail.com; dl-linux-imx
> > <linux-imx at nxp.com>; linux-media at vger.kernel.org;
> > linux-kernel at vger.kernel.org; linux-arm-kernel at lists.infradead.org
> > Subject: [EXT] Re: [PATCH] media: amphion: return error if format is
> > unsupported by vpu
> > 
> > Caution: EXT Email
> > 
> > Hi Ming Qian,
> > 
> > Le jeudi 19 mai 2022 à 15:28 +0800, Ming Qian a écrit :
> > > return error if format is unsupported by vpu, otherwise the vpu will
> > > be stalled at decoding
> > 
> > I have a reasonable doubt about this patch. I don't think such a case should
> > be
> > reachable by users. Normally, calls to S_FMT should ensure the driver format
> > state is valid on both ends but modifying the relevant structures. As an
> > example, for decoders, setting the CODEC (OUTPUT queue) format, may
> > change the raw format (CAPTURE queue) implicitly to prevent this situation.
> > Are we certain this change isn't papering around some missing format
> > propagation ?
> > 
> > regards,
> > Nicolas
> > 
> 
> Hi Nicolas,
>     You're right, it's not reachable currently.
>     And there are some formats supported by VPU, but I didn't add support in
> driver, as they are not defined in kernel yet.
> So if someone wants to enable them in future, and if he only adds a format
> into vdec_formats[] without modifying the vpu_malone part , then he can
> enum_fmt and set_fmt successfully, but meet vpu hang without any error
> message.
> 	I think driver should report an error in case of the new format is
> not implemented fully.

Fair point, but it should be bug_on or at least an error trace.

regards,
Nicolas

> 
> Ming
> 
> > > 
> > > Signed-off-by: Ming Qian <ming.qian at nxp.com>
> > > ---
> > >  drivers/media/platform/amphion/vpu_malone.c | 2 ++
> > >  drivers/media/platform/amphion/vpu_v4l2.c   | 4 ++--
> > >  2 files changed, 4 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/media/platform/amphion/vpu_malone.c
> > > b/drivers/media/platform/amphion/vpu_malone.c
> > > index f29c223eefce..0930b6ba8c42 100644
> > > --- a/drivers/media/platform/amphion/vpu_malone.c
> > > +++ b/drivers/media/platform/amphion/vpu_malone.c
> > > @@ -610,6 +610,8 @@ static int vpu_malone_set_params(struct
> > vpu_shared_addr *shared,
> > >       enum vpu_malone_format malone_format;
> > > 
> > >       malone_format =
> > vpu_malone_format_remap(params->codec_format);
> > > +     if (malone_format == MALONE_FMT_NULL)
> > > +             return -EINVAL;
> > >       iface->udata_buffer[instance].base = params->udata.base;
> > >       iface->udata_buffer[instance].slot_size = params->udata.size;
> > > 
> > > diff --git a/drivers/media/platform/amphion/vpu_v4l2.c
> > > b/drivers/media/platform/amphion/vpu_v4l2.c
> > > index 446f07d09d0b..89b88e063e45 100644
> > > --- a/drivers/media/platform/amphion/vpu_v4l2.c
> > > +++ b/drivers/media/platform/amphion/vpu_v4l2.c
> > > @@ -500,10 +500,10 @@ static int vpu_vb2_start_streaming(struct
> > vb2_queue *q, unsigned int count)
> > >                 fmt->sizeimage[1], fmt->bytesperline[1],
> > >                 fmt->sizeimage[2], fmt->bytesperline[2],
> > >                 q->num_buffers);
> > > -     call_void_vop(inst, start, q->type);
> > > +     ret = call_vop(inst, start, q->type);
> > >       vb2_clear_last_buffer_dequeued(q);
> > > 
> > > -     return 0;
> > > +     return ret;
> > >  }
> > > 
> > >  static void vpu_vb2_stop_streaming(struct vb2_queue *q)
>