[alsa-devel] [PATCH 1/2] ALSA: pcm: Yet finer pending signal check in OSS read/write loop

[Takashi Iwai]

PCM OSS emulation has the nested inner loops, and the loops in
snd_pcm_oss_read3() and write3() have no pending signal check, so
potentially they can hog for too long time for processing.
Add the extra check there.

While we're at it, a slight code cleanup using the standard macro for
the PCM state check is used.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/core/oss/pcm_oss.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 481ab0e94ffa..5e009a444d9d 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -1221,8 +1221,7 @@ snd_pcm_sframes_t snd_pcm_oss_write3(struct snd_pcm_substream *substream, const
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	int ret;
 	while (1) {
-		if (runtime->status->state == SNDRV_PCM_STATE_XRUN ||
-		    runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) {
+		if (!snd_pcm_running(substream)) {
 #ifdef OSS_DEBUG
 			pcm_dbg(substream->pcm,
 				"pcm_oss: write: recovering from %s\n",
@@ -1241,6 +1240,8 @@ snd_pcm_sframes_t snd_pcm_oss_write3(struct snd_pcm_substream *substream, const
 		/* has not been started */
 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED)
 			return -EAGAIN;
+		if (signal_pending(current))
+			return -ERESTARTSYS;
 	}
 	return ret;
 }
@@ -1278,10 +1279,11 @@ snd_pcm_sframes_t snd_pcm_oss_read3(struct snd_pcm_substream *substream, char *p
 				if (ret < 0)
 					break;
 			}
-			continue;
-		}
-		if (ret != -ESTRPIPE)
+		} else if (ret != -ESTRPIPE) {
 			break;
+		}
+		if (signal_pending(current))
+			return -ERESTARTSYS;
 	}
 	return ret;
 }
-- 
2.16.3