[ALSA] OSS PCM emulation - The final fix for SNDCTL_DSP_GETOPTR problem

ALSA<-OSS emulation
The problem was negative result (info.bytes) in a specific condition at
playback startup.

Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 5 insertions, 2 deletions

diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 468fca8894d9..203470df5857 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -1539,10 +1539,13 @@ static int snd_pcm_oss_get_ptr(snd_pcm_oss_file_t *pcm_oss_file, int stream, str
         } else {
                 delay = snd_pcm_oss_bytes(substream, delay) + fixup;
                 info.blocks = delay / runtime->oss.period_bytes;
-                if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+                if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+                        if (runtime->oss.bytes == 0)
+                                delay = 0;
                         info.bytes = (runtime->oss.bytes - delay) & INT_MAX;
-                else
+                } else {
                         info.bytes = (runtime->oss.bytes + delay) & INT_MAX;
+                }
         }
         if (copy_to_user(_info, &info, sizeof(info)))
                 return -EFAULT;