From 6594ad829a98d5a9fe720d8d182a4e50fc81953a Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 13 Dec 2007 16:15:41 -0300 Subject: V4L/DVB (6817): Cleanup kernel thread and provide overrun detection The previous code were a little bit messy. Cleans it up. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/vivi.c | 73 ++++++++++++++++++++++++++-------------------- 1 file changed, 41 insertions(+), 32 deletions(-) diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c index 004209d54498..c9d23633fe42 100644 --- a/drivers/media/video/vivi.c +++ b/drivers/media/video/vivi.c @@ -425,48 +425,57 @@ static void vivi_thread_tick(struct vivi_dmaqueue *dma_q) spin_unlock(&dev->slock); } +#define frames_to_ms(frames) \ + ((frames * WAKE_NUMERATOR * 1000) / WAKE_DENOMINATOR) + static void vivi_sleep(struct vivi_dmaqueue *dma_q) { struct vivi_dev *dev = container_of(dma_q, struct vivi_dev, vidq); - int timeout; + int timeout, running_time; DECLARE_WAITQUEUE(wait, current); dprintk(dev, 1, "%s dma_q=0x%08lx\n", __FUNCTION__, (unsigned long)dma_q); add_wait_queue(&dma_q->wq, &wait); - if (!kthread_should_stop()) { - dma_q->frame++; - - /* Calculate time to wake up */ - timeout = dma_q->ini_jiffies+ - msecs_to_jiffies((dma_q->frame*WAKE_NUMERATOR * 1000) - / WAKE_DENOMINATOR) - jiffies; - - if (timeout <= 0) { - int old = dma_q->frame; - dma_q->frame = (jiffies_to_msecs(jiffies - - dma_q->ini_jiffies) * - WAKE_DENOMINATOR) / - (WAKE_NUMERATOR * 1000) + 1; - - timeout = dma_q->ini_jiffies+ - msecs_to_jiffies((dma_q->frame * - WAKE_NUMERATOR * 1000) - / WAKE_DENOMINATOR) - jiffies; - - dprintk(dev, 1, "underrun, losed %d frames. " - "Now, frame is %d. Waking on %d jiffies\n", - dma_q->frame-old, dma_q->frame, timeout); - } else - dprintk(dev, 1, "will sleep for %i jiffies\n", - timeout); - - vivi_thread_tick(dma_q); - - schedule_timeout_interruptible(timeout); - } + if (kthread_should_stop()) + goto stop_task; + + running_time = jiffies - dma_q->ini_jiffies; + dma_q->frame++; + + /* Calculate time to wake up */ + timeout = msecs_to_jiffies(frames_to_ms(dma_q->frame)) - running_time; + + if (timeout > msecs_to_jiffies(frames_to_ms(2)) || timeout <= 0) { + int old = dma_q->frame; + int nframes; + + dma_q->frame = (jiffies_to_msecs(running_time) / + frames_to_ms(1)) + 1; + + timeout = msecs_to_jiffies(frames_to_ms(dma_q->frame)) + - running_time; + + if (unlikely (timeout <= 0)) + timeout = 1; + + nframes = (dma_q->frame > old)? + dma_q->frame - old : old - dma_q->frame; + + dprintk(dev, 1, "%ld: %s %d frames. " + "Current frame is %d. Will sleep for %d jiffies\n", + jiffies, + (dma_q->frame > old)? "Underrun, losed" : "Overrun of", + nframes, dma_q->frame, timeout); + } else + dprintk(dev, 1, "will sleep for %d jiffies\n", timeout); + + vivi_thread_tick(dma_q); + + schedule_timeout_interruptible(timeout); +stop_task: remove_wait_queue(&dma_q->wq, &wait); try_to_freeze(); } -- cgit v1.2.2