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authorDavid Henningsson <david.henningsson@canonical.com>2013-11-05 04:41:07 +0100
committerTakashi Iwai <tiwai@suse.de>2013-11-05 07:46:38 +0100
commite3e35f750fff74e701c8913fd7dd714e37a848cd (patch)
tree9ff01befeba4df75fb7de66006df16d579fe7b08
parent0dca01c37a68017fe7112b46bc4b48c927db18c6 (diff)
downloadlinux-e3e35f750fff74e701c8913fd7dd714e37a848cd.tar.bz2
ALSA: usb - For class 2 devices, use channel map from altsettings
The channel config from the streaming descriptor is probably a better indicator of the channel map than the input terminal. Use the input terminal's channel map as fallback only. Signed-off-by: David Henningsson <david.henningsson@canonical.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--sound/usb/stream.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index b43b6eec3227..badd1d6d175d 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -587,6 +587,7 @@ int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
num_channels = as->bNrChannels;
format = le32_to_cpu(as->bmFormats);
+ chconfig = le32_to_cpu(as->bmChannelConfig);
/* lookup the terminal associated to this interface
* to extract the clock */
@@ -594,7 +595,8 @@ int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
as->bTerminalLink);
if (input_term) {
clock = input_term->bCSourceID;
- chconfig = le32_to_cpu(input_term->bmChannelConfig);
+ if (!chconfig && (num_channels == input_term->bNrChannels))
+ chconfig = le32_to_cpu(input_term->bmChannelConfig);
break;
}