ALSA: pcm - A helper function to compose PCM stream name for debug prints

Use a common helper function for the PCM stream name displayed in
XRUN and buffer-pointer debug prints.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/pcm_lib.c

@@ -136,6 +136,16 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
 			dump_stack();			\
 	} while (0)
 
+static void pcm_debug_name(struct snd_pcm_substream *substream,
+			   char *name, size_t len)
+{
+	snprintf(name, len, "pcmC%dD%d%c:%d",
+		 substream->pcm->card->number,
+		 substream->pcm->device,
+		 substream->stream ? 'c' : 'p',
+		 substream->number);
+}
+
 static void xrun(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
@@ -144,10 +154,9 @@ static void xrun(struct snd_pcm_substream *substream)
 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
 	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 	if (xrun_debug(substream, 1)) {
-		snd_printd(KERN_DEBUG "XRUN: pcmC%dD%d%c\n",
-			   substream->pcm->card->number,
-			   substream->pcm->device,
-			   substream->stream ? 'c' : 'p');
+		char name[16];
+		pcm_debug_name(substream, name, sizeof(name));
+		snd_printd(KERN_DEBUG "XRUN: %s\n", name);
 		dump_stack_on_xrun(substream);
 	}
 }
@@ -163,9 +172,11 @@ snd_pcm_update_hw_ptr_pos(struct snd_pcm_substream *substream,
 		return pos; /* XRUN */
 	if (pos >= runtime->buffer_size) {
 		if (printk_ratelimit()) {
-			snd_printd(KERN_ERR  "BUG: stream = %i, pos = 0x%lx, "
+			char name[16];
+			pcm_debug_name(substream, name, sizeof(name));
+			snd_printd(KERN_ERR  "BUG: %s, pos = 0x%lx, "
 				   "buffer size = 0x%lx, period size = 0x%lx\n",
-				   substream->stream, pos, runtime->buffer_size,
+				   name, pos, runtime->buffer_size,
 				   runtime->period_size);
 		}
 		pos = 0;