ALSA: snd-usb: move calls to usb_set_interface

The rework of the snd-usb endpoint logic moved the calls to
snd_usb_set_interface() into the snd_usb_endpoint implemenation. This
changed the order in which these calls are issued to the device, and
thereby caused regressions for some webcams.

Fix this by moving the calls back to pcm.c for now to make it work again
and use snd_usb_endpoint_activate() to really tear down all remaining
URBs in the flight, consequently fixing another regression caused by USB
packets on the wire after altsetting 0 has been selected.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Reported-and-tested-by: Philipp Dreimann <philipp@dreimann.net>
Reported-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 35 insertions, 22 deletions

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index f0ede13..a1298f3 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -261,19 +261,6 @@ static void stop_endpoints(struct snd_usb_substream *subs,
 				      force, can_sleep, wait);
 }
 
-static int activate_endpoints(struct snd_usb_substream *subs)
-{
-	if (subs->sync_endpoint) {
-		int ret;
-
-		ret = snd_usb_endpoint_activate(subs->sync_endpoint);
-		if (ret < 0)
-			return ret;
-	}
-
-	return snd_usb_endpoint_activate(subs->data_endpoint);
-}
-
 static int deactivate_endpoints(struct snd_usb_substream *subs)
 {
 	int reta, retb;
@@ -314,6 +301,33 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 	if (fmt == subs->cur_audiofmt)
 		return 0;
 
+	/* close the old interface */
+	if (subs->interface >= 0 && subs->interface != fmt->iface) {
+		err = usb_set_interface(subs->dev, subs->interface, 0);
+		if (err < 0) {
+			snd_printk(KERN_ERR "%d:%d:%d: return to setting 0 failed (%d)\n",
+				dev->devnum, fmt->iface, fmt->altsetting, err);
+			return -EIO;
+		}
+		subs->interface = -1;
+		subs->altset_idx = 0;
+	}
+
+	/* set interface */
+	if (subs->interface != fmt->iface ||
+	    subs->altset_idx != fmt->altset_idx) {
+		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
+		if (err < 0) {
+			snd_printk(KERN_ERR "%d:%d:%d: usb_set_interface failed (%d)\n",
+				   dev->devnum, fmt->iface, fmt->altsetting, err);
+			return -EIO;
+		}
+		snd_printdd(KERN_INFO "setting usb interface %d:%d\n",
+				fmt->iface, fmt->altsetting);
+		subs->interface = fmt->iface;
+		subs->altset_idx = fmt->altset_idx;
+	}
+
 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
 						   alts, fmt->endpoint, subs->direction,
 						   SND_USB_ENDPOINT_TYPE_DATA);
@@ -460,12 +474,6 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 		mutex_lock(&subs->stream->chip->shutdown_mutex);
 		/* format changed */
 		stop_endpoints(subs, 0, 0, 0);
-		deactivate_endpoints(subs);
-
-		ret = activate_endpoints(subs);
-		if (ret < 0)
-			goto unlock;
-
 		ret = snd_usb_endpoint_set_params(subs->data_endpoint, hw_params, fmt,
 						  subs->sync_endpoint);
 		if (ret < 0)
@@ -500,6 +508,7 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream)
 	subs->period_bytes = 0;
 	mutex_lock(&subs->stream->chip->shutdown_mutex);
 	stop_endpoints(subs, 0, 1, 1);
+	deactivate_endpoints(subs);
 	mutex_unlock(&subs->stream->chip->shutdown_mutex);
 	return snd_pcm_lib_free_vmalloc_buffer(substream);
 }
@@ -938,16 +947,20 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
 
 static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
 {
-	int ret;
 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
 	struct snd_usb_substream *subs = &as->substream[direction];
 
 	stop_endpoints(subs, 0, 0, 0);
-	ret = deactivate_endpoints(subs);
+
+	if (!as->chip->shutdown && subs->interface >= 0) {
+		usb_set_interface(subs->dev, subs->interface, 0);
+		subs->interface = -1;
+	}
+
 	subs->pcm_substream = NULL;
 	snd_usb_autosuspend(subs->stream->chip);
 
-	return ret;
+	return 0;
 }
 
 /* Since a URB can handle only a single linear buffer, we must use double