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Subject: Re: [RFC PATCH v6 6/9] media: tegra: Add Tegra210 Video input driver
To:     Dmitry Osipenko <digetx@gmail.com>, <thierry.reding@gmail.com>,
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From:   Sowjanya Komatineni <skomatineni@nvidia.com>
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On 4/6/20 2:11 PM, Dmitry Osipenko wrote:
> External email: Use caution opening links or attachments
>
>
> 07.04.2020 00:02, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82:
>>>>>>> Am I understanding correctly that this thread will take 100% CPU,
>>>>>>> spinning here, if more than 2 frame-captures queued?
>>>>>> on more than 2 frames captures, it breaks thread and on next wakeup =
it
>>>>>> continues
>>>>> The wait_event() won't wait if condition is true.
>>>> condition is checked when waitqueue is woken up
>>> https://elixir.bootlin.com/linux/v5.6.2/source/include/linux/wait.h#L46=
2
>> process is put to sleep until the condition evaluates to true or signal
>> is received.
>>
>> condition is checked each time the waitqueue head is woken up.
> This is a wrong assumption in accordance to the code.

when every buffer is available as long as we are in streaming, we should=20
process it.

So if wake up happens when list has buffer, it will be processed but at=20
a time we limit processing 2 simultaneous buffer capture starts only.