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

Dmitry Osipenko
2020-04-10T19:45:38Z

10.04.2020 21:59, Sowjanya Komatineni пишет:
...
>> It's still not clear to me how the "pre-queued buffers" will be limited.
>> I'll take another look at the v7.
>
> OK, but I don't understand what you mean by limit on pre-queued buffers.
>
> I was saying vb2 queue has min_buffers_needed which was set to 3 where
> streaming will start only after 3 buffers got queued up.
>
> Regarding outstanding condition check to make sure no more than 2 syncpt
> trigger requests are in FIFO I added it to be safe where mostly we may
> not hit and also I only see capture start thread holding for it during
> initial frame capture as it issues single shot for 1st 2 buffers capture
> and holds 3 buffers which is already queued till at least one of those 2
> issued capture is done to make sure of not triggering syncpt condition
> when fifo already has 2 pending.
>
> In v7, will remove setting min_buffers_needed and also outstanding
> syncpt trigger check.

Okay, seems I got what you're saying. Yes, the check should be removed.
It's impossible to get the frame-start event while capture of the
previous buffer is in-progress.