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>
This commit is contained in:
David Henningsson 2013-11-05 04:41:08 +01:00 committed by Takashi Iwai
parent e3e35f750f
commit 504333df8b

View File

@ -662,7 +662,6 @@ int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
* (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 @@ int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
/* 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) {