ALSA: usbmixer: bail out early when parsing audio class v2 descriptors
This is just a quick hack that needs to be removed once the new units
defined by the audio class v2.0 standard are supported.
However, it allows using these devices for now, without mixer support.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/usbmixer.c b/sound/usb/usbmixer.c
index ca79495..42bb95c 100644
--- a/sound/usb/usbmixer.c
+++ b/sound/usb/usbmixer.c
@@ -2258,7 +2258,8 @@
};
struct usb_mixer_interface *mixer;
struct snd_info_entry *entry;
- int err;
+ struct usb_host_interface *host_iface;
+ int err, protocol;
strcpy(chip->card->mixername, "USB Mixer");
@@ -2275,6 +2276,16 @@
return -ENOMEM;
}
+ host_iface = &usb_ifnum_to_if(chip->dev, ctrlif)->altsetting[0];
+ protocol = host_iface->desc.bInterfaceProtocol;
+
+ /* FIXME! */
+ if (protocol != UAC_VERSION_1) {
+ snd_printk(KERN_WARNING "mixer interface protocol 0x%02x not yet supported\n",
+ protocol);
+ return 0;
+ }
+
if ((err = snd_usb_mixer_controls(mixer)) < 0 ||
(err = snd_usb_mixer_status_create(mixer)) < 0)
goto _error;