From 3702b082281929cf1bdf14f67eb0619aab58b496 Mon Sep 17 00:00:00 2001 From: Mark Hills Date: Sat, 24 Oct 2009 12:59:35 +0100 Subject: [PATCH] ALSA: snd-usb-caiaq: Missing lock around use of buffer positions Fix a race which causes snd_pcm_update_hw_ptr_pos() to report a bug. Signed-off-by: Mark Hills Acked-by: Daniel Mack Signed-off-by: Takashi Iwai --- sound/usb/caiaq/audio.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/sound/usb/caiaq/audio.c b/sound/usb/caiaq/audio.c index 121af0644fd9..e76017cd5acf 100644 --- a/sound/usb/caiaq/audio.c +++ b/sound/usb/caiaq/audio.c @@ -269,16 +269,22 @@ snd_usb_caiaq_pcm_pointer(struct snd_pcm_substream *sub) { int index = sub->number; struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub); + snd_pcm_uframes_t ptr; + + spin_lock(&dev->spinlock); if (dev->input_panic || dev->output_panic) - return SNDRV_PCM_POS_XRUN; + ptr = SNDRV_PCM_POS_XRUN; if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK) - return bytes_to_frames(sub->runtime, + ptr = bytes_to_frames(sub->runtime, dev->audio_out_buf_pos[index]); else - return bytes_to_frames(sub->runtime, + ptr = bytes_to_frames(sub->runtime, dev->audio_in_buf_pos[index]); + + spin_unlock(&dev->spinlock); + return ptr; } /* operators for both playback and capture */ -- 2.20.1