On 08/11/2021 19:42, Niklas Söderlund wrote:
> 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?
Yes. And use vb2_queue_error_with_event in other drivers as well where
applicable. Hmm, it can't be called vb2_ since it is v4l2_ specific, so
perhaps v4l2_queue_error which takes a video_device and a vb2_queue as
arguments. I don't want this just in rcar since it makes perfect sense
as a generic event for such situations.
Regards,
Hans
>
>>
>> Regards,
>>
>> Hans
>>
>>> + break;
>>> + default:
>>> + break;
>>> + }
>>> +
>>> + v4l2_event_queue(&vin->vdev, event);
>>> break;
>>> default:
>>> break;
>>>
>>
>
