ALSA: usb - Don't trust the channel config if the channel count changed
In case the channel count of the input terminal is not the same as
the channel count of the streaming descriptor, the channel config of
the input terminal can not be trusted. Instead fall back to a default
(guessed) channel map.
This was found on a Logitech USB Headset.
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index badd1d6d..d737d0e 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -662,7 +662,6 @@
* (fp->maxpacksize & 0x7ff);
fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol, iface_no);
fp->clock = clock;
- fp->chmap = convert_chmap(num_channels, chconfig, protocol);
/* some quirks for attributes here */
@@ -698,12 +697,16 @@
/* ok, let's parse further... */
if (snd_usb_parse_audio_format(chip, fp, format, fmt, stream) < 0) {
kfree(fp->rate_table);
- kfree(fp->chmap);
kfree(fp);
fp = NULL;
continue;
}
+ /* Create chmap */
+ if (fp->channels != num_channels)
+ chconfig = 0;
+ fp->chmap = convert_chmap(fp->channels, chconfig, protocol);
+
snd_printdd(KERN_INFO "%d:%u:%d: add audio endpoint %#x\n", dev->devnum, iface_no, altno, fp->endpoint);
err = snd_usb_add_audio_stream(chip, stream, fp);
if (err < 0) {