Messages in this thread | | | Subject | Re: [RFC PATCH v6 6/9] media: tegra: Add Tegra210 Video input driver | From | Sowjanya Komatineni <> | Date | Mon, 6 Apr 2020 13:38:11 -0700 |
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On 4/6/20 1:37 PM, Dmitry Osipenko wrote: > External email: Use caution opening links or attachments > > > 06.04.2020 23:20, Sowjanya Komatineni пишет: >> On 4/6/20 1:02 PM, Dmitry Osipenko wrote: >>> External email: Use caution opening links or attachments >>> >>> >>> 04.04.2020 04:25, Sowjanya Komatineni пишет: >>> ... >>>> +static int chan_capture_kthread_start(void *data) >>>> +{ >>>> + struct tegra_vi_channel *chan = data; >>>> + struct tegra_channel_buffer *buf; >>>> + int err = 0; >>>> + int caps_inflight; >>>> + >>>> + set_freezable(); >>>> + >>>> + while (1) { >>>> + try_to_freeze(); >>>> + >>>> + wait_event_interruptible(chan->start_wait, >>>> + !list_empty(&chan->capture) || >>>> + kthread_should_stop()); >>> Is it really okay that list_empty() isn't protected with a lock? >>> >>> Why wait_event is "interruptible"? >> To allow it to sleep until wakeup on thread it to avoid constant >> checking for condition even when no buffers are ready, basically to >> prevent blocking. > So the "interrupt" is for getting event about kthread_should_stop(), > correct? also to prevent blocking and to let is sleep and wakeup based on wait queue to evaluate condition to proceed with the task >
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