Hi!
OK thanks for checking. So probably only n_gsm channel 1 is for normal Qualcomm at commands, and then channel 2 and others are commands implemented by Motorola on the mdm6600.
I guess we'd have to add support for reading and writing to /dev/gsmtty2 at least as it looks like these cannot be accessed via /dev/ttyUSB4. Or at least I have not figured out any other way to access them.
Hmm or maybe there is some way to select where qmi to tunnels the AT commands to? Some kind of channel type paramenter like n_gsm has?
Anyways, for trying to figure out things for alsamixer, I tested that ngsm 2 "AT+EACC=3,0" is not related to cpcap audio register settings and the mic is enabled during the call with Pavel's patch with alsamixer "Mode" set to either "Call" or "Normal". Also speaker keeps working during the call toggling between "Call" and "Normal". "Voice" in alsamixer does also control the speaker volume during the call. And setting the second "Speaker" from "Voice" to "HiFi" mutes the speaker.
Take a look at the patch. Selecting "call" does something at hardware level, selecting "normal" is a nop.
Sorry for confusion.
Yes, that patch needs more work.
Pavel