On 4/6/20 1:45 PM, Dmitry Osipenko wrote:
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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