https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound?id=2d3391ec0ecca37efb6bc995906292f47522b471
The difference between std channel map and alt channel map
You need to modify the driver by adding lines without "+" at the end of the two routines
+ err = snd_pcm_add_chmap_ctls(pcm, SNDRV_PCM_STREAM_PLAYBACK, + snd_pcm_alt_chmaps, cm->max_channels, 0, + NULL); + if (err < 0) + return err; +
https:/ /git.kernel. org/cgit/ linux/kernel/ git/tiwai/ sound.git/ commit/ sound?id= 2d3391ec0ecca37 efb6bc995906292 f47522b471
The difference between std channel map and alt channel map
You need to modify the driver by adding lines without "+" at the end of the two routines
+ err = snd_pcm_ add_chmap_ ctls(pcm, SNDRV_PCM_ STREAM_ PLAYBACK,
+ snd_pcm_alt_chmaps, cm->max_channels, 0,
+ NULL);
+ if (err < 0)
+ return err;
+