ALSA: Fix SNDCTL_DSP_RESET ioctl for OSS emulation

In OSS emulation, SNDCTL_DSP_RESET ioctl needs the reset of the internal
buffer state in addition to drop of the running streams.  Otherwise the
succeeding access becomes inconsistent.

Tested-by: Amit Nagal <helloin.amit@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 11 insertions, 8 deletions

diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 5c8c7dff8ede..b753ec661fcf 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -1510,16 +1510,19 @@ static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __use
 static int snd_pcm_oss_reset(struct snd_pcm_oss_file *pcm_oss_file)
 {
         struct snd_pcm_substream *substream;
+        struct snd_pcm_runtime *runtime;
+        int i;
 
-        substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
-        if (substream != NULL) {
-                snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
-                substream->runtime->oss.prepare = 1;
-        }
-        substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
-        if (substream != NULL) {
+        for (i = 0; i < 2; i++) { 
+                substream = pcm_oss_file->streams[i];
+                if (!substream)
+                        continue;
+                runtime = substream->runtime;
                 snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
-                substream->runtime->oss.prepare = 1;
+                runtime->oss.prepare = 1;
+                runtime->oss.buffer_used = 0;
+                runtime->oss.prev_hw_ptr_period = 0;
+                runtime->oss.period_ptr = 0;
         }
         return 0;
 }