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 13:50:35 -0700 |
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On 4/6/20 1:45 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()); >> + /* >> + * 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? on more than 2 frames captures, it breaks thread and on next wakeup it continues
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