Commit 96fbf771 authored Oct 15, 2009 by Devin Heitmueller Committed by Mauro Carvalho Chehab Nov 07, 2009

V4L/DVB (13190): em28xx: fix panic that can occur when starting audio streaming



Because the counters were not reset when starting up streaming, they would
be reused from the previous run.  This can result in cases such that when the
second instance of streaming starts up, the "cnt" variable in
em28xx_audio_isocirq() can end up being negative, resulting in attempting to
write to memory before the start of runtime->dma_area (as well as having a
negative number of bytes to copy).

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
CC: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

parent 2de26c0a

drivers/media/video/em28xx/em28xx-audio.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -383,6 +383,11 @@ static int snd_em28xx_hw_capture_free(struct snd_pcm_substream *substream)

		static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
		{
		struct em28xx *dev = snd_pcm_substream_chip(substream);

		dev->adev.hwptr_done_capture = 0;
		dev->adev.capture_transfer_done = 0;

		return 0;
		}

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