staging: bcm2835-audio: Drop useless running flag and check

The running flag of alsa_stream is basically useless.  The running
state is strictly controlled in ALSA PCM core side, hence the check in
PCM trigger and close callbacks are superfluous.

Also, the prefill ack at trigger start became superfluous nowadays
with the ALSA PCM core update.

Let's rip them off.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c

@@ -187,19 +187,6 @@ static int snd_bcm2835_playback_close(struct snd_pcm_substream *substream)
 
 	audio_info("Alsa close\n");
 
-	/*
-	 * Call stop if it's still running. This happens when app
-	 * is force killed and we don't get a stop trigger.
-	 */
-	if (alsa_stream->running) {
-		int err;
-
-		err = bcm2835_audio_stop(alsa_stream);
-		alsa_stream->running = 0;
-		if (err)
-			audio_error(" Failed to STOP alsa device\n");
-	}
-
 	alsa_stream->period_size = 0;
 	alsa_stream->buffer_size = 0;
 
@@ -324,27 +311,13 @@ static int snd_bcm2835_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
-		audio_debug("bcm2835_AUDIO_TRIGGER_START running=%d\n",
-			alsa_stream->running);
-		if (!alsa_stream->running) {
 		err = bcm2835_audio_start(alsa_stream);
-			if (!err) {
-				alsa_stream->pcm_indirect.hw_io =
-					alsa_stream->pcm_indirect.hw_data =
-					bytes_to_frames(runtime,
-					alsa_stream->pos);
-				substream->ops->ack(substream);
-				alsa_stream->running = 1;
+		if (!err)
 			alsa_stream->draining = 1;
-			} else {
+		else
 			audio_error(" Failed to START alsa device (%d)\n", err);
-			}
-		}
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
-		audio_debug
-			("bcm2835_AUDIO_TRIGGER_STOP running=%d draining=%d\n",
-			alsa_stream->running, runtime->status->state == SNDRV_PCM_STATE_DRAINING);
 		if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
 			audio_info("DRAINING\n");
 			alsa_stream->draining = 1;
@@ -352,12 +325,9 @@ static int snd_bcm2835_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 			audio_info("DROPPING\n");
 			alsa_stream->draining = 0;
 		}
-		if (alsa_stream->running) {
 		err = bcm2835_audio_stop(alsa_stream);
 		if (err != 0)
 			audio_error(" Failed to STOP alsa device (%d)\n", err);
-			alsa_stream->running = 0;
-		}
 		break;
 	default:
 		err = -EINVAL;

drivers/staging/vc04_services/bcm2835-audio/bcm2835.h

@@ -121,7 +121,6 @@ struct bcm2835_alsa_stream {
 
 	spinlock_t lock;
 
-	int running;
 	int draining;
 
 	int channels;