--- zzzz-none-000/linux-3.10.107/sound/usb/pcm.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/sound/usb/pcm.c	2021-02-04 17:41:59.000000000 +0000
@@ -80,7 +80,7 @@
 	unsigned int hwptr_done;
 
 	subs = (struct snd_usb_substream *)substream->runtime->private_data;
-	if (subs->stream->chip->shutdown)
+	if (atomic_read(&subs->stream->chip->shutdown))
 		return SNDRV_PCM_POS_XRUN;
 	spin_lock(&subs->lock);
 	hwptr_done = subs->hwptr_done;
@@ -159,6 +159,8 @@
 	unsigned char data[1];
 	int err;
 
+	if (get_iface_desc(alts)->bNumEndpoints < 1)
+		return -EINVAL;
 	ep = get_endpoint(alts, 0)->bEndpointAddress;
 
 	data[0] = 1;
@@ -166,8 +168,8 @@
 				   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
 				   UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
 				   data, sizeof(data))) < 0) {
-		snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH\n",
-			   dev->devnum, iface, ep);
+		usb_audio_err(chip, "%d:%d: cannot set enable PITCH\n",
+			      iface, ep);
 		return err;
 	}
 
@@ -187,8 +189,8 @@
 				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
 				   UAC2_EP_CS_PITCH << 8, 0,
 				   data, sizeof(data))) < 0) {
-		snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH (v2)\n",
-			   dev->devnum, iface, fmt->altsetting);
+		usb_audio_err(chip, "%d:%d: cannot set enable PITCH (v2)\n",
+			      iface, fmt->altsetting);
 		return err;
 	}
 
@@ -202,13 +204,11 @@
 		       struct usb_host_interface *alts,
 		       struct audioformat *fmt)
 {
-	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
-
 	/* if endpoint doesn't have pitch control, bail out */
 	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
 		return 0;
 
-	switch (altsd->bInterfaceProtocol) {
+	switch (fmt->protocol) {
 	case UAC_VERSION_1:
 	default:
 		return init_pitch_v1(chip, iface, alts, fmt);
@@ -218,7 +218,7 @@
 	}
 }
 
-static int start_endpoints(struct snd_usb_substream *subs, bool can_sleep)
+static int start_endpoints(struct snd_usb_substream *subs)
 {
 	int err;
 
@@ -228,10 +228,10 @@
 	if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
 		struct snd_usb_endpoint *ep = subs->data_endpoint;
 
-		snd_printdd(KERN_DEBUG "Starting data EP @%p\n", ep);
+		dev_dbg(&subs->dev->dev, "Starting data EP @%p\n", ep);
 
 		ep->data_subs = subs;
-		err = snd_usb_endpoint_start(ep, can_sleep);
+		err = snd_usb_endpoint_start(ep);
 		if (err < 0) {
 			clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags);
 			return err;
@@ -243,24 +243,24 @@
 		struct snd_usb_endpoint *ep = subs->sync_endpoint;
 
 		if (subs->data_endpoint->iface != subs->sync_endpoint->iface ||
-		    subs->data_endpoint->alt_idx != subs->sync_endpoint->alt_idx) {
+		    subs->data_endpoint->altsetting != subs->sync_endpoint->altsetting) {
 			err = usb_set_interface(subs->dev,
 						subs->sync_endpoint->iface,
-						subs->sync_endpoint->alt_idx);
+						subs->sync_endpoint->altsetting);
 			if (err < 0) {
-				snd_printk(KERN_ERR
-					   "%d:%d:%d: cannot set interface (%d)\n",
-					   subs->dev->devnum,
+				clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
+				dev_err(&subs->dev->dev,
+					   "%d:%d: cannot set interface (%d)\n",
 					   subs->sync_endpoint->iface,
-					   subs->sync_endpoint->alt_idx, err);
+					   subs->sync_endpoint->altsetting, err);
 				return -EIO;
 			}
 		}
 
-		snd_printdd(KERN_DEBUG "Starting sync EP @%p\n", ep);
+		dev_dbg(&subs->dev->dev, "Starting sync EP @%p\n", ep);
 
 		ep->sync_slave = subs->data_endpoint;
-		err = snd_usb_endpoint_start(ep, can_sleep);
+		err = snd_usb_endpoint_start(ep);
 		if (err < 0) {
 			clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
 			return err;
@@ -284,18 +284,192 @@
 	}
 }
 
-static int deactivate_endpoints(struct snd_usb_substream *subs)
+static int search_roland_implicit_fb(struct usb_device *dev, int ifnum,
+				     unsigned int altsetting,
+				     struct usb_host_interface **alts,
+				     unsigned int *ep)
+{
+	struct usb_interface *iface;
+	struct usb_interface_descriptor *altsd;
+	struct usb_endpoint_descriptor *epd;
+
+	iface = usb_ifnum_to_if(dev, ifnum);
+	if (!iface || iface->num_altsetting < altsetting + 1)
+		return -ENOENT;
+	*alts = &iface->altsetting[altsetting];
+	altsd = get_iface_desc(*alts);
+	if (altsd->bAlternateSetting != altsetting ||
+	    altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
+	    (altsd->bInterfaceSubClass != 2 &&
+	     altsd->bInterfaceProtocol != 2   ) ||
+	    altsd->bNumEndpoints < 1)
+		return -ENOENT;
+	epd = get_endpoint(*alts, 0);
+	if (!usb_endpoint_is_isoc_in(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
+					USB_ENDPOINT_USAGE_IMPLICIT_FB)
+		return -ENOENT;
+	*ep = epd->bEndpointAddress;
+	return 0;
+}
+
+static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
+					 struct usb_device *dev,
+					 struct usb_interface_descriptor *altsd,
+					 unsigned int attr)
+{
+	struct usb_host_interface *alts;
+	struct usb_interface *iface;
+	unsigned int ep;
+
+	/* Implicit feedback sync EPs consumers are always playback EPs */
+	if (subs->direction != SNDRV_PCM_STREAM_PLAYBACK)
+		return 0;
+
+	switch (subs->stream->chip->usb_id) {
+	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
+	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
+		ep = 0x81;
+		iface = usb_ifnum_to_if(dev, 3);
+
+		if (!iface || iface->num_altsetting == 0)
+			return -EINVAL;
+
+		alts = &iface->altsetting[1];
+		goto add_sync_ep;
+		break;
+	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
+	case USB_ID(0x0763, 0x2081):
+		ep = 0x81;
+		iface = usb_ifnum_to_if(dev, 2);
+
+		if (!iface || iface->num_altsetting == 0)
+			return -EINVAL;
+
+		alts = &iface->altsetting[1];
+		goto add_sync_ep;
+	}
+	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
+	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
+	    altsd->bInterfaceProtocol == 2 &&
+	    altsd->bNumEndpoints == 1 &&
+	    USB_ID_VENDOR(subs->stream->chip->usb_id) == 0x0582 /* Roland */ &&
+	    search_roland_implicit_fb(dev, altsd->bInterfaceNumber + 1,
+				      altsd->bAlternateSetting,
+				      &alts, &ep) >= 0) {
+		goto add_sync_ep;
+	}
+
+	/* No quirk */
+	return 0;
+
+add_sync_ep:
+	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
+						   alts, ep, !subs->direction,
+						   SND_USB_ENDPOINT_TYPE_DATA);
+	if (!subs->sync_endpoint)
+		return -EINVAL;
+
+	subs->data_endpoint->sync_master = subs->sync_endpoint;
+
+	return 0;
+}
+
+static int set_sync_endpoint(struct snd_usb_substream *subs,
+			     struct audioformat *fmt,
+			     struct usb_device *dev,
+			     struct usb_host_interface *alts,
+			     struct usb_interface_descriptor *altsd)
 {
-	int reta, retb;
+	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
+	unsigned int ep, attr;
+	bool implicit_fb;
+	int err;
+
+	/* we need a sync pipe in async OUT or adaptive IN mode */
+	/* check the number of EP, since some devices have broken
+	 * descriptors which fool us.  if it has only one EP,
+	 * assume it as adaptive-out or sync-in.
+	 */
+	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
+
+	if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
+		(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {
+
+		/*
+		 * In these modes the notion of sync_endpoint is irrelevant.
+		 * Reset pointers to avoid using stale data from previously
+		 * used settings, e.g. when configuration and endpoints were
+		 * changed
+		 */
 
-	reta = snd_usb_endpoint_deactivate(subs->sync_endpoint);
-	retb = snd_usb_endpoint_deactivate(subs->data_endpoint);
+		subs->sync_endpoint = NULL;
+		subs->data_endpoint->sync_master = NULL;
+	}
 
-	if (reta < 0)
-		return reta;
+	err = set_sync_ep_implicit_fb_quirk(subs, dev, altsd, attr);
+	if (err < 0)
+		return err;
 
-	if (retb < 0)
-		return retb;
+	if (altsd->bNumEndpoints < 2)
+		return 0;
+
+	if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
+			     attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
+	    (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
+		return 0;
+
+	/*
+	 * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
+	 * if we don't find a sync endpoint, as on M-Audio Transit. In case of
+	 * error fall back to SYNC mode and don't create sync endpoint
+	 */
+
+	/* check sync-pipe endpoint */
+	/* ... and check descriptor size before accessing bSynchAddress
+	   because there is a version of the SB Audigy 2 NX firmware lacking
+	   the audio fields in the endpoint descriptors */
+	if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
+	    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
+	     get_endpoint(alts, 1)->bSynchAddress != 0)) {
+		dev_err(&dev->dev,
+			"%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
+			   fmt->iface, fmt->altsetting,
+			   get_endpoint(alts, 1)->bmAttributes,
+			   get_endpoint(alts, 1)->bLength,
+			   get_endpoint(alts, 1)->bSynchAddress);
+		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
+			return 0;
+		return -EINVAL;
+	}
+	ep = get_endpoint(alts, 1)->bEndpointAddress;
+	if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
+	    ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
+	     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
+		dev_err(&dev->dev,
+			"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
+			   fmt->iface, fmt->altsetting,
+			   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
+		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
+			return 0;
+		return -EINVAL;
+	}
+
+	implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
+			== USB_ENDPOINT_USAGE_IMPLICIT_FB;
+
+	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
+						   alts, ep, !subs->direction,
+						   implicit_fb ?
+							SND_USB_ENDPOINT_TYPE_DATA :
+							SND_USB_ENDPOINT_TYPE_SYNC);
+	if (!subs->sync_endpoint) {
+		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
+			return 0;
+		return -EINVAL;
+	}
+
+	subs->data_endpoint->sync_master = subs->sync_endpoint;
 
 	return 0;
 }
@@ -309,9 +483,7 @@
 	struct usb_host_interface *alts;
 	struct usb_interface_descriptor *altsd;
 	struct usb_interface *iface;
-	unsigned int ep, attr;
-	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
-	int err, implicit_fb = 0;
+	int err;
 
 	iface = usb_ifnum_to_if(dev, fmt->iface);
 	if (WARN_ON(!iface))
@@ -328,8 +500,9 @@
 	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);
+			dev_err(&dev->dev,
+				"%d:%d: return to setting 0 failed (%d)\n",
+				fmt->iface, fmt->altsetting, err);
 			return -EIO;
 		}
 		subs->interface = -1;
@@ -339,14 +512,20 @@
 	/* set interface */
 	if (subs->interface != fmt->iface ||
 	    subs->altset_idx != fmt->altset_idx) {
+
+		err = snd_usb_select_mode_quirk(subs, fmt);
+		if (err < 0)
+			return -EIO;
+
 		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);
+			dev_err(&dev->dev,
+				"%d:%d: usb_set_interface failed (%d)\n",
+				fmt->iface, fmt->altsetting, err);
 			return -EIO;
 		}
-		snd_printdd(KERN_INFO "setting usb interface %d:%d\n",
-				fmt->iface, fmt->altsetting);
+		dev_dbg(&dev->dev, "setting usb interface %d:%d\n",
+			fmt->iface, fmt->altsetting);
 		subs->interface = fmt->iface;
 		subs->altset_idx = fmt->altset_idx;
 
@@ -356,106 +535,22 @@
 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
 						   alts, fmt->endpoint, subs->direction,
 						   SND_USB_ENDPOINT_TYPE_DATA);
+
 	if (!subs->data_endpoint)
 		return -EINVAL;
 
-	/* we need a sync pipe in async OUT or adaptive IN mode */
-	/* check the number of EP, since some devices have broken
-	 * descriptors which fool us.  if it has only one EP,
-	 * assume it as adaptive-out or sync-in.
-	 */
-	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
-
-	switch (subs->stream->chip->usb_id) {
-	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
-	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
-		if (is_playback) {
-			implicit_fb = 1;
-			ep = 0x81;
-			iface = usb_ifnum_to_if(dev, 3);
-
-			if (!iface || iface->num_altsetting == 0)
-				return -EINVAL;
-
-			alts = &iface->altsetting[1];
-			goto add_sync_ep;
-		}
-		break;
-	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
-	case USB_ID(0x0763, 0x2081):
-		if (is_playback) {
-			implicit_fb = 1;
-			ep = 0x81;
-			iface = usb_ifnum_to_if(dev, 2);
-
-			if (!iface || iface->num_altsetting == 0)
-				return -EINVAL;
-
-			alts = &iface->altsetting[1];
-			goto add_sync_ep;
-		}
-	}
-
-	if (((is_playback && attr == USB_ENDPOINT_SYNC_ASYNC) ||
-	     (!is_playback && attr == USB_ENDPOINT_SYNC_ADAPTIVE)) &&
-	    altsd->bNumEndpoints >= 2) {
-		/* check sync-pipe endpoint */
-		/* ... and check descriptor size before accessing bSynchAddress
-		   because there is a version of the SB Audigy 2 NX firmware lacking
-		   the audio fields in the endpoint descriptors */
-		if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
-		    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
-		     get_endpoint(alts, 1)->bSynchAddress != 0 &&
-		     !implicit_fb)) {
-			snd_printk(KERN_ERR "%d:%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
-				   dev->devnum, fmt->iface, fmt->altsetting,
-				   get_endpoint(alts, 1)->bmAttributes,
-				   get_endpoint(alts, 1)->bLength,
-				   get_endpoint(alts, 1)->bSynchAddress);
-			return -EINVAL;
-		}
-		ep = get_endpoint(alts, 1)->bEndpointAddress;
-		if (!implicit_fb &&
-		    get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
-		    (( is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
-		     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
-			snd_printk(KERN_ERR "%d:%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
-				   dev->devnum, fmt->iface, fmt->altsetting,
-				   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
-			return -EINVAL;
-		}
-
-		implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
-				== USB_ENDPOINT_USAGE_IMPLICIT_FB;
-
-add_sync_ep:
-		subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
-							   alts, ep, !subs->direction,
-							   implicit_fb ?
-								SND_USB_ENDPOINT_TYPE_DATA :
-								SND_USB_ENDPOINT_TYPE_SYNC);
-		if (!subs->sync_endpoint)
-			return -EINVAL;
-
-		subs->data_endpoint->sync_master = subs->sync_endpoint;
-	}
+	err = set_sync_endpoint(subs, fmt, dev, alts, altsd);
+	if (err < 0)
+		return err;
 
-	if ((err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt)) < 0)
+	err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt);
+	if (err < 0)
 		return err;
 
 	subs->cur_audiofmt = fmt;
 
 	snd_usb_set_format_quirk(subs, fmt);
 
-#if 0
-	printk(KERN_DEBUG
-	       "setting done: format = %d, rate = %d..%d, channels = %d\n",
-	       fmt->format, fmt->rate_min, fmt->rate_max, fmt->channels);
-	printk(KERN_DEBUG
-	       "  datapipe = 0x%0x, syncpipe = 0x%0x\n",
-	       subs->datapipe, subs->syncpipe);
-#endif
-
 	return 0;
 }
 
@@ -466,20 +561,23 @@
  * - Requested PCM format is not supported.
  * - Requested sample rate is not supported.
  */
-static int match_endpoint_audioformats(struct audioformat *fp,
-	struct audioformat *match, int rate,
-	snd_pcm_format_t pcm_format)
+static int match_endpoint_audioformats(struct snd_usb_substream *subs,
+				       struct audioformat *fp,
+				       struct audioformat *match, int rate,
+				       snd_pcm_format_t pcm_format)
 {
 	int i;
 	int score = 0;
 
 	if (fp->channels < 1) {
-		snd_printdd("%s: (fmt @%p) no channels\n", __func__, fp);
+		dev_dbg(&subs->dev->dev,
+			"%s: (fmt @%p) no channels\n", __func__, fp);
 		return 0;
 	}
 
 	if (!(fp->formats & pcm_format_to_bits(pcm_format))) {
-		snd_printdd("%s: (fmt @%p) no match for format %d\n", __func__,
+		dev_dbg(&subs->dev->dev,
+			"%s: (fmt @%p) no match for format %d\n", __func__,
 			fp, pcm_format);
 		return 0;
 	}
@@ -491,7 +589,8 @@
 		}
 	}
 	if (!score) {
-		snd_printdd("%s: (fmt @%p) no match for rate %d\n", __func__,
+		dev_dbg(&subs->dev->dev,
+			"%s: (fmt @%p) no match for rate %d\n", __func__,
 			fp, rate);
 		return 0;
 	}
@@ -499,7 +598,8 @@
 	if (fp->channels == match->channels)
 		score++;
 
-	snd_printdd("%s: (fmt @%p) score %d\n", __func__, fp, score);
+	dev_dbg(&subs->dev->dev,
+		"%s: (fmt @%p) score %d\n", __func__, fp, score);
 
 	return score;
 }
@@ -523,13 +623,15 @@
 						   subs->pcm_format,
 						   subs->channels,
 						   subs->period_bytes,
+						   0, 0,
 						   subs->cur_rate,
 						   subs->cur_audiofmt,
 						   NULL);
 
 	/* Try to find the best matching audioformat. */
 	list_for_each_entry(fp, &sync_subs->fmt_list, list) {
-		int score = match_endpoint_audioformats(fp, subs->cur_audiofmt,
+		int score = match_endpoint_audioformats(subs,
+							fp, subs->cur_audiofmt,
 			subs->cur_rate, subs->pcm_format);
 
 		if (score > cur_score) {
@@ -539,7 +641,8 @@
 	}
 
 	if (unlikely(sync_fp == NULL)) {
-		snd_printk(KERN_ERR "%s: no valid audioformat for sync ep %x found\n",
+		dev_err(&subs->dev->dev,
+			"%s: no valid audioformat for sync ep %x found\n",
 			__func__, sync_subs->ep_num);
 		return -EINVAL;
 	}
@@ -551,7 +654,8 @@
 	if (sync_fp->channels != subs->channels) {
 		sync_period_bytes = (subs->period_bytes / subs->channels) *
 			sync_fp->channels;
-		snd_printdd("%s: adjusted sync ep period bytes (%d -> %d)\n",
+		dev_dbg(&subs->dev->dev,
+			"%s: adjusted sync ep period bytes (%d -> %d)\n",
 			__func__, subs->period_bytes, sync_period_bytes);
 	}
 
@@ -559,6 +663,7 @@
 					  subs->pcm_format,
 					  sync_fp->channels,
 					  sync_period_bytes,
+					  0, 0,
 					  subs->cur_rate,
 					  sync_fp,
 					  NULL);
@@ -581,6 +686,8 @@
 					  subs->pcm_format,
 					  subs->channels,
 					  subs->period_bytes,
+					  subs->period_frames,
+					  subs->buffer_periods,
 					  subs->cur_rate,
 					  subs->cur_audiofmt,
 					  subs->sync_endpoint);
@@ -617,22 +724,24 @@
 
 	subs->pcm_format = params_format(hw_params);
 	subs->period_bytes = params_period_bytes(hw_params);
+	subs->period_frames = params_period_size(hw_params);
+	subs->buffer_periods = params_periods(hw_params);
 	subs->channels = params_channels(hw_params);
 	subs->cur_rate = params_rate(hw_params);
 
 	fmt = find_format(subs);
 	if (!fmt) {
-		snd_printd(KERN_DEBUG "cannot set format: format = %#x, rate = %d, channels = %d\n",
+		dev_dbg(&subs->dev->dev,
+			"cannot set format: format = %#x, rate = %d, channels = %d\n",
 			   subs->pcm_format, subs->cur_rate, subs->channels);
 		return -EINVAL;
 	}
 
-	down_read(&subs->stream->chip->shutdown_rwsem);
-	if (subs->stream->chip->shutdown)
-		ret = -ENODEV;
-	else
-		ret = set_format(subs, fmt);
-	up_read(&subs->stream->chip->shutdown_rwsem);
+	ret = snd_usb_lock_shutdown(subs->stream->chip);
+	if (ret < 0)
+		return ret;
+	ret = set_format(subs, fmt);
+	snd_usb_unlock_shutdown(subs->stream->chip);
 	if (ret < 0)
 		return ret;
 
@@ -655,12 +764,12 @@
 	subs->cur_audiofmt = NULL;
 	subs->cur_rate = 0;
 	subs->period_bytes = 0;
-	down_read(&subs->stream->chip->shutdown_rwsem);
-	if (!subs->stream->chip->shutdown) {
+	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
 		stop_endpoints(subs, true);
-		deactivate_endpoints(subs);
+		snd_usb_endpoint_deactivate(subs->sync_endpoint);
+		snd_usb_endpoint_deactivate(subs->data_endpoint);
+		snd_usb_unlock_shutdown(subs->stream->chip);
 	}
-	up_read(&subs->stream->chip->shutdown_rwsem);
 	return snd_pcm_lib_free_vmalloc_buffer(substream);
 }
 
@@ -678,15 +787,13 @@
 	int ret;
 
 	if (! subs->cur_audiofmt) {
-		snd_printk(KERN_ERR "usbaudio: no format is specified!\n");
+		dev_err(&subs->dev->dev, "no format is specified!\n");
 		return -ENXIO;
 	}
 
-	down_read(&subs->stream->chip->shutdown_rwsem);
-	if (subs->stream->chip->shutdown) {
-		ret = -ENODEV;
-		goto unlock;
-	}
+	ret = snd_usb_lock_shutdown(subs->stream->chip);
+	if (ret < 0)
+		return ret;
 	if (snd_BUG_ON(!subs->data_endpoint)) {
 		ret = -EIO;
 		goto unlock;
@@ -732,10 +839,10 @@
 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
 	 * updates for all URBs would happen at the same time when starting */
 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
-		ret = start_endpoints(subs, true);
+		ret = start_endpoints(subs);
 
  unlock:
-	up_read(&subs->stream->chip->shutdown_rwsem);
+	snd_usb_unlock_shutdown(subs->stream->chip);
 	return ret;
 }
 
@@ -1137,9 +1244,11 @@
 
 	stop_endpoints(subs, true);
 
-	if (!as->chip->shutdown && subs->interface >= 0) {
+	if (subs->interface >= 0 &&
+	    !snd_usb_lock_shutdown(subs->stream->chip)) {
 		usb_set_interface(subs->dev, subs->interface, 0);
 		subs->interface = -1;
+		snd_usb_unlock_shutdown(subs->stream->chip);
 	}
 
 	subs->pcm_substream = NULL;
@@ -1171,7 +1280,8 @@
 	for (i = 0; i < urb->number_of_packets; i++) {
 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
-			snd_printdd(KERN_ERR "frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
+			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
+				i, urb->iso_frame_desc[i].status);
 			// continue;
 		}
 		bytes = urb->iso_frame_desc[i].actual_length;
@@ -1181,7 +1291,8 @@
 		if (bytes % (runtime->sample_bits >> 3) != 0) {
 			int oldbytes = bytes;
 			bytes = frames * stride;
-			snd_printdd(KERN_ERR "Corrected urb data len. %d->%d\n",
+			dev_warn(&subs->dev->dev,
+				 "Corrected urb data len. %d->%d\n",
 							oldbytes, bytes);
 		}
 		/* update the current pointer */
@@ -1274,6 +1385,56 @@
 			subs->hwptr_done++;
 		}
 	}
+	if (subs->hwptr_done >= runtime->buffer_size * stride)
+		subs->hwptr_done -= runtime->buffer_size * stride;
+}
+
+static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb,
+			int offset, int stride, unsigned int bytes)
+{
+	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
+
+	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
+		/* err, the transferred area goes over buffer boundary. */
+		unsigned int bytes1 =
+			runtime->buffer_size * stride - subs->hwptr_done;
+		memcpy(urb->transfer_buffer + offset,
+		       runtime->dma_area + subs->hwptr_done, bytes1);
+		memcpy(urb->transfer_buffer + offset + bytes1,
+		       runtime->dma_area, bytes - bytes1);
+	} else {
+		memcpy(urb->transfer_buffer + offset,
+		       runtime->dma_area + subs->hwptr_done, bytes);
+	}
+	subs->hwptr_done += bytes;
+	if (subs->hwptr_done >= runtime->buffer_size * stride)
+		subs->hwptr_done -= runtime->buffer_size * stride;
+}
+
+static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs,
+				      struct urb *urb, int stride,
+				      unsigned int bytes)
+{
+	__le32 packet_length;
+	int i;
+
+	/* Put __le32 length descriptor at start of each packet. */
+	for (i = 0; i < urb->number_of_packets; i++) {
+		unsigned int length = urb->iso_frame_desc[i].length;
+		unsigned int offset = urb->iso_frame_desc[i].offset;
+
+		packet_length = cpu_to_le32(length);
+		offset += i * sizeof(packet_length);
+		urb->iso_frame_desc[i].offset = offset;
+		urb->iso_frame_desc[i].length += sizeof(packet_length);
+		memcpy(urb->transfer_buffer + offset,
+		       &packet_length, sizeof(packet_length));
+		copy_to_urb(subs, urb, offset + sizeof(packet_length),
+			    stride, length);
+	}
+	/* Adjust transfer size accordingly. */
+	bytes += urb->number_of_packets * sizeof(packet_length);
+	return bytes;
 }
 
 static void prepare_playback_urb(struct snd_usb_substream *subs,
@@ -1291,6 +1452,7 @@
 	frames = 0;
 	urb->number_of_packets = 0;
 	spin_lock_irqsave(&subs->lock, flags);
+	subs->frame_limit += ep->max_urb_frames;
 	for (i = 0; i < ctx->packets; i++) {
 		if (ctx->packet_size[i])
 			counts = ctx->packet_size[i];
@@ -1305,6 +1467,7 @@
 		subs->transfer_done += counts;
 		if (subs->transfer_done >= runtime->period_size) {
 			subs->transfer_done -= runtime->period_size;
+			subs->frame_limit = 0;
 			period_elapsed = 1;
 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
 				if (subs->transfer_done > 0) {
@@ -1327,8 +1490,10 @@
 				break;
 			}
 		}
-		if (period_elapsed &&
-		    !snd_usb_endpoint_implicit_feedback_sink(subs->data_endpoint)) /* finish at the period boundary */
+		/* finish at the period boundary or after enough frames */
+		if ((period_elapsed ||
+				subs->transfer_done >= subs->frame_limit) &&
+		    !snd_usb_endpoint_implicit_feedback_sink(ep))
 			break;
 	}
 	bytes = frames * ep->stride;
@@ -1347,27 +1512,17 @@
 		}
 
 		subs->hwptr_done += bytes;
+		if (subs->hwptr_done >= runtime->buffer_size * stride)
+			subs->hwptr_done -= runtime->buffer_size * stride;
 	} else {
 		/* usual PCM */
-		if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
-			/* err, the transferred area goes over buffer boundary. */
-			unsigned int bytes1 =
-				runtime->buffer_size * stride - subs->hwptr_done;
-			memcpy(urb->transfer_buffer,
-			       runtime->dma_area + subs->hwptr_done, bytes1);
-			memcpy(urb->transfer_buffer + bytes1,
-			       runtime->dma_area, bytes - bytes1);
-		} else {
-			memcpy(urb->transfer_buffer,
-			       runtime->dma_area + subs->hwptr_done, bytes);
-		}
-
-		subs->hwptr_done += bytes;
+		if (!subs->tx_length_quirk)
+			copy_to_urb(subs, urb, 0, stride, bytes);
+		else
+			bytes = copy_to_urb_quirk(subs, urb, stride, bytes);
+			/* bytes is now amount of outgoing data */
 	}
 
-	if (subs->hwptr_done >= runtime->buffer_size * stride)
-		subs->hwptr_done -= runtime->buffer_size * stride;
-
 	/* update delay with exact number of samples queued */
 	runtime->delay = subs->last_delay;
 	runtime->delay += frames;
@@ -1377,6 +1532,14 @@
 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
 
+	if (subs->trigger_tstamp_pending_update) {
+		/* this is the first actual URB submitted,
+		 * update trigger timestamp to reflect actual start time
+		 */
+		snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
+		subs->trigger_tstamp_pending_update = false;
+	}
+
 	spin_unlock_irqrestore(&subs->lock, flags);
 	urb->transfer_buffer_length = bytes;
 	if (period_elapsed)
@@ -1463,6 +1626,7 @@
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
+		subs->trigger_tstamp_pending_update = true;
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
@@ -1491,7 +1655,7 @@
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
-		err = start_endpoints(subs, false);
+		err = start_endpoints(subs);
 		if (err < 0)
 			return err;