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Subject: Re: [RFC PATCH v6 6/9] media: tegra: Add Tegra210 Video input driver
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From:   Dmitry Osipenko <digetx@gmail.com>
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Date:   Wed, 8 Apr 2020 01:08:27 +0300
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08.04.2020 00:08, Sowjanya Komatineni пишет:
...
>>> 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.