Messages in this thread | | | Subject | Re: [RFC PATCH v11 6/9] media: tegra: Add Tegra210 Video input driver | From | Sowjanya Komatineni <> | Date | Thu, 30 Apr 2020 09:04:40 -0700 |
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On 4/30/20 7:13 AM, Dmitry Osipenko wrote: > 30.04.2020 17:02, Dmitry Osipenko пишет: >> 30.04.2020 16:56, Dmitry Osipenko пишет: >>> 30.04.2020 01:00, Sowjanya Komatineni пишет: >>>> +static int chan_capture_kthread_finish(void *data) >>>> +{ >>>> + struct tegra_vi_channel *chan = data; >>>> + struct tegra_channel_buffer *buf; >>>> + >>>> + set_freezable(); >>>> + >>>> + while (1) { >>>> + try_to_freeze(); >>> I guess it won't be great to freeze in the middle of a capture process, so: >>> if (list_empty(&chan->done)) >>> try_to_freeze(); >> And here should be some locking protection in order not race with the >> chan_capture_kthread_start because kthread_finish could freeze before >> kthread_start. > Or maybe both start / finish threads should simply be allowed to freeze > only when both capture and done lists are empty. > > if (list_empty(&chan->capture) && > list_empty(&chan->done)) > try_to_freeze();
good to freeze when not in middle of the frame capture but why should we not allow freeze in between captures?
Other drivers do allow freeze in between frame captures.
I guess we can freeze before dequeue for capture and in finish thread we can freeze after capture done. This also don't need to check for list_empty with freeze to allow between frame captures.
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