Hi Hans,
On 2021-11-08 18:36:25 +0100, Hans Verkuil wrote:
> On 08/11/2021 17:02, Niklas Söderlund wrote:
> > When a subdevice signals a transfer error stop the VIN in addition to
> > informing user-space of the event.
> >
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> > Reviewed-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> > ---
> > * Changes since v3
> > - Switch to new V4L2_EVENT_XFER_ERROR from V4L2_EVENT_EOS.
> > - Call vb2_queue_error() when encountering the event.
> >
> > * Changes since v2
> > - Log using vin_dbg() instead of v4l2_info().
> > ---
> > drivers/media/platform/rcar-vin/rcar-v4l2.c | 17 ++++++++++++++++-
> > 1 file changed, 16 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/platform/rcar-vin/rcar-v4l2.c b/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > index a5bfa76fdac6e55a..bf17fdefe90aabf5 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > @@ -992,9 +992,24 @@ void rvin_v4l2_unregister(struct rvin_dev *vin)
> > static void rvin_notify_video_device(struct rvin_dev *vin,
> > unsigned int notification, void *arg)
> > {
> > + const struct v4l2_event *event;
> > +
> > switch (notification) {
> > case V4L2_DEVICE_NOTIFY_EVENT:
> > - v4l2_event_queue(&vin->vdev, arg);
> > + event = arg;
> > +
> > + switch (event->type) {
> > + case V4L2_EVENT_XFER_ERROR:
> > + vin_dbg(vin,
> > + "Subdevice signaled transfer error, stopping.\n");
> > + rvin_stop_streaming(vin);
> > + vb2_queue_error(&vin->queue);
>
> Hmm, wouldn't it be the case that every driver that calls vb2_queue_error()
> would also have to send this new event? Would it be possible to modify
> vb2_queue_error() to raise this event? I haven't analyzed all the drivers
> that call this function to see if that makes sense.
>
> Perhaps a separate new function vb2_queue_error_with_event() would also be
> an option.
I think that maybe a good idea, but I think that would be needed on-top
of this work as I can't really test it. Here the rcar-csi2.ko is a
subdevice which detects the error condition and generates the event. And
this code is in rcar-vin.ko, the video device driver which reacts to the
event and then forwards it to user-space.
Or am I misunderstanding you? And you think I should remove the
v4l2_event_queue() below in favor of a new vb2_queue_error_with_event()
call?
>
> Regards,
>
> Hans
>
> > + break;
> > + default:
> > + break;
> > + }
> > +
> > + v4l2_event_queue(&vin->vdev, event);
> > break;
> > default:
> > break;
> >
>
--
Kind Regards,
Niklas Söderlund
