ALSA: usb-audio: fix oops due to cleanup race when disconnecting

[linux-flexiantxendom0-natty.git] / sound / usb / pcm.c

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 4132522..e3f6805 100644 (file)
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -361,6 +361,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
        }
 
        if (changed) {
+               mutex_lock(&subs->stream->chip->shutdown_mutex);
                /* format changed */
                snd_usb_release_substream_urbs(subs, 0);
                /* influenced: period_bytes, channels, rate, format, */
@@ -368,6 +369,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
                                                  params_rate(hw_params),
                                                  snd_pcm_format_physical_width(params_format(hw_params)) *
                                                        params_channels(hw_params));
+               mutex_unlock(&subs->stream->chip->shutdown_mutex);
        }
 
        return ret;
@@ -385,8 +387,9 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream)
        subs->cur_audiofmt = NULL;
        subs->cur_rate = 0;
        subs->period_bytes = 0;
-       if (!subs->stream->chip->shutdown)
-               snd_usb_release_substream_urbs(subs, 0);
+       mutex_lock(&subs->stream->chip->shutdown_mutex);
+       snd_usb_release_substream_urbs(subs, 0);
+       mutex_unlock(&subs->stream->chip->shutdown_mutex);
        return snd_pcm_lib_free_vmalloc_buffer(substream);
 }