ALSA: pcm: Return 0 when size < start_threshold in capture

In __snd_pcm_lib_xfer(), when capture, if state is PREPARED and size is less than start_threshold nothing can be done. As there is no error, 0 is returned.

Signed-off-by Ricardo Biehl Pasquali <[email protected]>

---

version 2:
The code was not changed. Just resubmitting to follow the rules from Documentation/process/submitting-patches.rst.

pcm_lib.c renamed from pcm_lib.c.orig +9 -5

@@ -2125,7 +2125,7 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(str
 	pcm_transfer_f transfer;
 	bool nonblock;
 	bool is_playback;
-	int err;
+	int err = 0;
 
 	err = pcm_sanity_check(substream);
 	if (err < 0)

@@ -2173,11 +2173,15 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(str
 		goto _end_unlock;
 
 	if (!is_playback &&
-	    runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
-	    size >= runtime->start_threshold) {
-		err = snd_pcm_start(substream);
-		if (err < 0)
+	    runtime->status->state == SNDRV_PCM_STATE_PREPARED) {
+		if (size >= runtime->start_threshold) {
+			err = snd_pcm_start(substream);
+			if (err < 0)
+				goto _end_unlock;
+		} else {
+			/* nothing to do */
 			goto _end_unlock;
+		}
 	}
 
 	runtime->twake = runtime->control->avail_min ? : 1;

Almost good, but still not perfect, unfortunately :) The patch should be applicable onto the kernel tree as is with -p1 option, i.e. the diff should be like
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c

But never mind, I'll apply this manually at this time, just keep the above in mind for the next time.

Quoted 6 lines · Takashi

Almost good, but still not perfect, unfortunately :) The patch should be applicable onto the kernel tree as is with -p1 option, i.e. the diff should be like
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c

Quoted 2 lines

But never mind, I'll apply this manually at this time, just keep the above in mind for the next time.

Ok, thank you!

The .orig thing is ok if I had used the full pathname?