ALSA: line6: Use incremental loop

Using a decremental loop without particular reasons worsens the
readability a lot.  Use incremental loops instead.
Tested-by: NChris Rorvick <chris@rorvick.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/usb/line6/capture.c

@@ -91,7 +91,7 @@ void line6_unlink_audio_in_urbs(struct snd_line6_pcm *line6pcm)
 {
 	unsigned int i;
 
-	for (i = LINE6_ISO_BUFFERS; i--;) {
+	for (i = 0; i < LINE6_ISO_BUFFERS; i++) {
 		if (test_bit(i, &line6pcm->active_urb_in)) {
 			if (!test_and_set_bit(i, &line6pcm->unlink_urb_in)) {
 				struct urb *u = line6pcm->urb_audio_in[i];
@@ -114,7 +114,7 @@ void line6_wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm)
 
 	do {
 		alive = 0;
-		for (i = LINE6_ISO_BUFFERS; i--;) {
+		for (i = 0; i < LINE6_ISO_BUFFERS; i++) {
 			if (test_bit(i, &line6pcm->active_urb_in))
 				alive++;
 		}

sound/usb/line6/pcm.c

@@ -273,7 +273,7 @@ static int snd_line6_control_playback_get(struct snd_kcontrol *kcontrol,
 	int i;
 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
 
-	for (i = 2; i--;)
+	for (i = 0; i < 2; i++)
 		ucontrol->value.integer.value[i] = line6pcm->volume_playback[i];
 
 	return 0;
@@ -286,7 +286,7 @@ static int snd_line6_control_playback_put(struct snd_kcontrol *kcontrol,
 	int i, changed = 0;
 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
 
-	for (i = 2; i--;)
+	for (i = 0; i < 2; i++)
 		if (line6pcm->volume_playback[i] !=
 		    ucontrol->value.integer.value[i]) {
 			line6pcm->volume_playback[i] =
@@ -330,7 +330,7 @@ static void line6_cleanup_pcm(struct snd_pcm *pcm)
 	int i;
 	struct snd_line6_pcm *line6pcm = snd_pcm_chip(pcm);
 
-	for (i = LINE6_ISO_BUFFERS; i--;) {
+	for (i = 0; i < LINE6_ISO_BUFFERS; i++) {
 		if (line6pcm->urb_audio_out[i]) {
 			usb_kill_urb(line6pcm->urb_audio_out[i]);
 			usb_free_urb(line6pcm->urb_audio_out[i]);

sound/usb/line6/playback.c

@@ -297,7 +297,7 @@ void line6_unlink_audio_out_urbs(struct snd_line6_pcm *line6pcm)
 {
 	unsigned int i;
 
-	for (i = LINE6_ISO_BUFFERS; i--;) {
+	for (i = 0; i < LINE6_ISO_BUFFERS; i++) {
 		if (test_bit(i, &line6pcm->active_urb_out)) {
 			if (!test_and_set_bit(i, &line6pcm->unlink_urb_out)) {
 				struct urb *u = line6pcm->urb_audio_out[i];
@@ -320,7 +320,7 @@ void line6_wait_clear_audio_out_urbs(struct snd_line6_pcm *line6pcm)
 
 	do {
 		alive = 0;
-		for (i = LINE6_ISO_BUFFERS; i--;) {
+		for (i = 0; i < LINE6_ISO_BUFFERS; i++) {
 			if (test_bit(i, &line6pcm->active_urb_out))
 				alive++;
 		}
@@ -366,14 +366,14 @@ static void audio_out_callback(struct urb *urb)
 	line6pcm->last_frame_out = urb->start_frame;
 
 	/* find index of URB */
-	for (index = LINE6_ISO_BUFFERS; index--;)
+	for (index = 0; index < LINE6_ISO_BUFFERS; index++)
 		if (urb == line6pcm->urb_audio_out[index])
 			break;
 
-	if (index < 0)
+	if (index >= LINE6_ISO_BUFFERS)
 		return;		/* URB has been unlinked asynchronously */
 
-	for (i = LINE6_ISO_PACKETS; i--;)
+	for (i = 0; i < LINE6_ISO_PACKETS; i++)
 		length += urb->iso_frame_desc[i].length;
 
 	spin_lock_irqsave(&line6pcm->lock_audio_out, flags);
@@ -390,7 +390,7 @@ static void audio_out_callback(struct urb *urb)
 
 	clear_bit(index, &line6pcm->active_urb_out);
 
-	for (i = LINE6_ISO_PACKETS; i--;)
+	for (i = 0; i < LINE6_ISO_PACKETS; i++)
 		if (urb->iso_frame_desc[i].status == -EXDEV) {
 			shutdown = 1;
 			break;