+static const struct snd_pcm_chmap_elem acer_pcm_chmaps[] = {
- { .channels = 2, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } }, + {
.channels = 4, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
SNDRV_CHMAP_LFE, SNDRV_CHMAP_NA } }, /* LFE only on left */
{ .channels = 4, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
{ .channels = 6,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
{ }
+};
After testing with ubuntu 15.10 alpha and modified snd-dummy
alsa-lib seem using the first channel map which has FL, FR and LFE , this mean that 2.1 profile always use your notebook internal speaker/subwoofer even when your notebook support 5.1 external speakers
this behaviour is different from those desktop with external 5.1 speakers using 2.1 profile
you may need to implement dynamic channel map which change when line out jack is plugged if you want to use 2.1 profile with external 5.1 speakers