ALSA: Add extra delay count in PCM

Added runtime->delay field to adjust the delayed samples for snd_pcm_delay().
Typically a hardware FIFO length is stored in this field, so that the
extra delay between hwptr and applptr can be computed.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index fc6f98e..cb769d4 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -587,14 +587,15 @@
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		status->avail = snd_pcm_playback_avail(runtime);
 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING ||
-		    runtime->status->state == SNDRV_PCM_STATE_DRAINING)
+		    runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
 			status->delay = runtime->buffer_size - status->avail;
-		else
+			status->delay += runtime->delay;
+		} else
 			status->delay = 0;
 	} else {
 		status->avail = snd_pcm_capture_avail(runtime);
 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
-			status->delay = status->avail;
+			status->delay = status->avail + runtime->delay;
 		else
 			status->delay = 0;
 	}
@@ -2404,6 +2405,7 @@
 			n = snd_pcm_playback_hw_avail(runtime);
 		else
 			n = snd_pcm_capture_avail(runtime);
+		n += runtime->delay;
 		break;
 	case SNDRV_PCM_STATE_XRUN:
 		err = -EPIPE;