ALSA: usb-audio: fix detection of vendor-specific device protocol settings
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>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/format.c b/sound/usb/format.c
index 3a13754..6914821 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -49,7 +49,8 @@
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 @@
format <<= 1;
break;
}
-
- default:
- return -EINVAL;
}
pcm_formats = 0;
@@ -384,6 +382,10 @@
* 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);
@@ -392,10 +394,6 @@
/* fp->channels is already set in this case */
ret = parse_audio_format_rates_v2(chip, fp);
break;
- default:
- snd_printk(KERN_ERR "%d:%u:%d : invalid protocol version %d\n",
- chip->dev->devnum, fp->iface, fp->altsetting, protocol);
- return -EINVAL;
}
if (fp->channels < 1) {
@@ -438,6 +436,10 @@
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);
@@ -456,10 +458,6 @@
ret = parse_audio_format_rates_v2(chip, fp);
break;
}
- default:
- snd_printk(KERN_ERR "%d:%u:%d : invalid protocol version %d\n",
- chip->dev->devnum, fp->iface, fp->altsetting, protocol);
- return -EINVAL;
}
return ret;