ALSA: usb-audio: fix detection of vendor-specific device protocol settings

commit a2acad8298a42b7be684a32fafaf83332bba9c2b upstream.

The Audio Class v2 support code in 2.6.35 added checks for the
bInterfaceProtocol field.  However, there are devices (usually those
detected by vendor-specific quirks) that do not have one of the
predefined values in this field, which made the driver reject them.

To fix this regression, restore the old behaviour, i.e., assume that
a device with an unknown bInterfaceProtocol field (other than
UAC_VERSION_2) has more or less UAC-v1-compatible descriptors.

[compile warning fixes by tiwai]

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

6 files changed, 32 insertions, 18 deletions

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 7a8ac1d81be..745bd782faa 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -216,6 +216,11 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 	}
 
 	switch (protocol) {
+	default:
+		snd_printdd(KERN_WARNING "unknown interface protocol %#02x, assuming v1\n",
+			    protocol);
+		/* fall through */
+
 	case UAC_VERSION_1: {
 		struct uac_ac_header_descriptor_v1 *h1 = control_header;
 
@@ -253,10 +258,6 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 
 		break;
 	}
-
-	default:
-		snd_printk(KERN_ERR "unknown protocol version 0x%02x\n", protocol);
-		return -EINVAL;
 	}
 
 	return 0;
diff --git a/sound/usb/clock.c b/sound/usb/clock.c
index b5855114667..aeda4c77839 100644
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -304,12 +304,11 @@ int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
 
 	switch (altsd->bInterfaceProtocol) {
 	case UAC_VERSION_1:
+	default:
 		return set_sample_rate_v1(chip, iface, alts, fmt, rate);
 
 	case UAC_VERSION_2:
 		return set_sample_rate_v2(chip, iface, alts, fmt, rate);
 	}
-
-	return -EINVAL;
 }
 
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 6f6596cf2b1..0aac6280001 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -274,6 +274,12 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 
 		/* get audio formats */
 		switch (protocol) {
+		default:
+			snd_printdd(KERN_WARNING "%d:%u:%d: unknown interface protocol %#02x, assuming v1\n",
+				    dev->devnum, iface_no, altno, protocol);
+			protocol = UAC_VERSION_1;
+			/* fall through */
+
 		case UAC_VERSION_1: {
 			struct uac_as_header_descriptor_v1 *as =
 				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
@@ -335,11 +341,6 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 				   dev->devnum, iface_no, altno, as->bTerminalLink);
 			continue;
 		}
-
-		default:
-			snd_printk(KERN_ERR "%d:%u:%d : unknown interface protocol %04x\n",
-				   dev->devnum, iface_no, altno, protocol);
-			continue;
 		}
 
 		/* get format type */
diff --git a/sound/usb/format.c b/sound/usb/format.c
index 30364aba79c..440d7c3cb00 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -49,7 +49,8 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
 	u64 pcm_formats;
 
 	switch (protocol) {
-	case UAC_VERSION_1: {
+	case UAC_VERSION_1:
+	default: {
 		struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
 		sample_width = fmt->bBitResolution;
 		sample_bytes = fmt->bSubframeSize;
@@ -64,9 +65,6 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
 		format <<= 1;
 		break;
 	}
-
-	default:
-		return -EINVAL;
 	}
 
 	pcm_formats = 0;
@@ -385,6 +383,10 @@ static int parse_audio_format_i(struct snd_usb_audio *chip,
 	 * audio class v2 uses class specific EP0 range requests for that.
 	 */
 	switch (protocol) {
+	default:
+		snd_printdd(KERN_WARNING "%d:%u:%d : invalid protocol version %d, assuming v1\n",
+			   chip->dev->devnum, fp->iface, fp->altsetting, protocol);
+		/* fall through */
 	case UAC_VERSION_1:
 		fp->channels = fmt->bNrChannels;
 		ret = parse_audio_format_rates_v1(chip, fp, (unsigned char *) fmt, 7);
@@ -435,6 +437,10 @@ static int parse_audio_format_ii(struct snd_usb_audio *chip,
 	fp->channels = 1;
 
 	switch (protocol) {
+	default:
+		snd_printdd(KERN_WARNING "%d:%u:%d : invalid protocol version %d, assuming v1\n",
+			   chip->dev->devnum, fp->iface, fp->altsetting, protocol);
+		/* fall through */
 	case UAC_VERSION_1: {
 		struct uac_format_type_ii_discrete_descriptor *fmt = _fmt;
 		brate = le16_to_cpu(fmt->wMaxBitRate);
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 736d134cc03..2a4377f42dd 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -2168,7 +2168,15 @@ int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
 	}
 
 	host_iface = &usb_ifnum_to_if(chip->dev, ctrlif)->altsetting[0];
-	mixer->protocol = get_iface_desc(host_iface)->bInterfaceProtocol;
+	switch (get_iface_desc(host_iface)->bInterfaceProtocol) {
+	case UAC_VERSION_1:
+	default:
+		mixer->protocol = UAC_VERSION_1;
+		break;
+	case UAC_VERSION_2:
+		mixer->protocol = UAC_VERSION_2;
+		break;
+	}
 
 	if ((err = snd_usb_mixer_controls(mixer)) < 0 ||
 	    (err = snd_usb_mixer_status_create(mixer)) < 0)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 456829882f4..b40a24853c1 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -173,13 +173,12 @@ int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
 
 	switch (altsd->bInterfaceProtocol) {
 	case UAC_VERSION_1:
+	default:
 		return init_pitch_v1(chip, iface, alts, fmt);
 
 	case UAC_VERSION_2:
 		return init_pitch_v2(chip, iface, alts, fmt);
 	}
-
-	return -EINVAL;
 }
 
 /*