Re: [RFC PATCH v11 6/9] media: tegra: Add Tegra210 Video input driver

[Dmitry Osipenko]

30.04.2020 17:02, Dmitry Osipenko ÐÐÑÐÑ:
> 30.04.2020 16:56, Dmitry Osipenko ÐÐÑÐÑ:
>> 30.04.2020 01:00, Sowjanya Komatineni ÐÐÑÐÑ:
>>> +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();