Re: [RFC PATCH v6 6/9] media: tegra: Add Tegra210 Video input driver

[Dmitry Osipenko]

08.04.2020 00:08, Sowjanya Komatineni ÐÐÑÐÑ:
...
>>> I think you need a semaphore with resource count = 2.
>> we hold on to issuing capture if more than 2 buffers are queued and it
>> continues only after fifo has min 1 slot empty
> 
> 
> Just want to close on this part of feedback. Hope above explanation is
> clear regarding triggering/issuing at max 2 frame capture to VI HW and
> also regarding capture threads where they use wait_event_interruptible
> to prevent blocking waiting for buffers to be available for captures.
> 
> So no changes related to this part are needed in v7.
>From what I see in the code, you "hold on" by making kthread to spin in
a busy-loop while caps_inflight >= SYNCPT_FIFO_DEPTH. So some change
should be needed to prevent this.

The wait_event_interruptible seems should be okay.