From ac9dd9d384b018f1e1c5a9a2686ab5605ce55818 Mon Sep 17 00:00:00 2001
From: Mark Hills <mark@pogo.org.uk>
Date: Sat, 24 Oct 2009 12:59:36 +0100
Subject: [PATCH] ALSA: snd-usb-caiaq: Lock on stream start/unpause
Fix a bug which can result in white noise from the driver after stream
start or unpause.
Signed-off-by: Mark Hills <mark@pogo.org.uk>
Acked-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/usb/caiaq/audio.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/sound/usb/caiaq/audio.c b/sound/usb/caiaq/audio.c
index e76017cd5acf1..86b2c3b92df53 100644
--- a/sound/usb/caiaq/audio.c
+++ b/sound/usb/caiaq/audio.c
@@ -62,10 +62,14 @@ static void
activate_substream(struct snd_usb_caiaqdev *dev,
struct snd_pcm_substream *sub)
{
+ spin_lock(&dev->spinlock);
+
if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
dev->sub_playback[sub->number] = sub;
else
dev->sub_capture[sub->number] = sub;
+
+ spin_unlock(&dev->spinlock);
}
static void