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 13:09:57 -0700 |
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On 4/30/20 1:08 PM, Sowjanya Komatineni wrote: > > On 4/30/20 1:06 PM, Dmitry Osipenko wrote: >> 30.04.2020 01:00, 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; >>> + >>> + set_freezable(); >>> + >>> + while (1) { >>> + try_to_freeze(); >>> + >>> + /* >>> + * Source is not streaming if error is non-zero. >>> + * So, do not dequeue buffers on error and let the thread >>> sleep >>> + * till kthread stop signal is received. >>> + */ >>> + wait_event_interruptible(chan->start_wait, >>> + kthread_should_stop() || >>> + (!list_empty(&chan->capture) && >>> + !err)); >> ... >>> +static void tegra_channel_buffer_queue(struct vb2_buffer *vb) >>> +{ >>> + struct tegra_vi_channel *chan = vb2_get_drv_priv(vb->vb2_queue); >>> + struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); >>> + struct tegra_channel_buffer *buf = to_tegra_channel_buffer(vbuf); >>> + >>> + /* put buffer into the capture queue */ >>> + spin_lock(&chan->start_lock); >>> + list_add_tail(&buf->queue, &chan->capture); >>> + spin_unlock(&chan->start_lock); >>> + >>> + /* wait up kthread for capture */ >>> + wake_up_interruptible(&chan->start_wait); >>> +} >> The V4L doc says that buffers could be enqueued before streaming is >> started. I guess it should be a trouble here, shouldn't it? >> >> https://elixir.bootlin.com/linux/v5.7-rc3/source/include/media/videobuf2-core.h#L379 >> > > what trouble are you referring here? > > I dont think so as we set min buffers needed as 2 always there will be > 2 per-queued buffers. typo* pre-queued buffers before streaming start > > But buffers from this queue will be dequeued only when ready to > processes in the capture thread >
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