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

Dmitry Osipenko
2020-04-06T20:45:34Z

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());
> + /*
> + * Frame start and MW_ACK_DONE syncpoint condition FIFOs are
> + * of max depth 2. So make sure max 2 capture requests are
> + * in process by the hardware at a time.
> + */
> + while (!(kthread_should_stop() || list_empty(&chan->capture))) {
> + caps_inflight = chan->capture_reqs - chan->sequence;
> + /*
> + * Source is not streaming if error is non-zero.
> + * So, do not dequeue buffers on capture error or when
> + * syncpoint requests in FIFO are full.
> + */
> + if (err || caps_inflight >= SYNCPT_FIFO_DEPTH)
> + break;

Am I understanding correctly that this thread will take 100% CPU,
spinning here, if more than 2 frame-captures queued?