Re: [gentoo-user] USB sound

[Peter Humphrey]

On Tuesday, 28 April 2020 14:18:52 BST Mark Knecht wrote:

Has KMail started misbehaving again? I'm certain I read a reply from Michael, 
but now there's no trace of it after a reboot (see below). Anyway, I created 
an /etc/asound.conf with the content he recommended. That gave me sound back. 
Thanks Michael.

> 1) First, if you really don't want the intel stuff loaded then either don't
> build it in your kernel or (easier - it's what I do) just blacklist the
> intel sound driver. The following link has some instructions which explain
> the process.

> https://www.techtimejourney.net/how-to-blacklist-a-sound-card-in-linux/

Thanks for the pointer, Mark. 

> Please provide the output of
>
> ls /proc/asound
> cat /proc/asound/cards
> cat /proc/asound/modules

# ls /proc/asound
card0  card2  Device   HDMI   modules  pcm  timers  version
card1  cards  devices  hwdep  oss      seq  USB

# cat /proc/asound/cards
 0 [HDMI           ]: HDA-Intel - HDA ATI HDMI
                      HDA ATI HDMI at 0xfbe60000 irq 59
 1 [USB            ]: USB-Audio - HD Webcam USB
                      HD Webcam USB HD Webcam USB at usb-0000:00:14.0-6, high 
speed
 2 [Device         ]: USB-Audio - USB Audio Device
                      C-Media Electronics Inc. USB Audio Device at 
usb-0000:00:14.0-13, full speed

# cat /proc/asound/modules
 0 snd_hda_intel
 1 snd_usb_audio
 2 snd_usb_audio

> 1) First, if you really don't want the intel stuff loaded then either don't
> build it in your kernel or (easier - it's what I do) just blacklist the
> intel sound driver. The following link has some instructions which explain
> the process.
>
> https://www.techtimejourney.net/how-to-blacklist-a-sound-card-in-linux/
>
> Restart Alsa and double check the cards and modules shown in /proc/asound.
>
> 2) As you are on KDE you likely have pulseaudio running. Run pavucontrol,
> run Firefox with some audio and see where you are sending Firefox audio.

Nope. No pulseaudio.

> 3) You probably don't have to mess with Alsa configuration itself to fix
> this so keep it simple for now. We can go there later if need be.

Meanwhile there are a few complications. First, I also have a webcam with a 
microphone. I should have unplugged this before asking my question.

Second, there's a sound driver in my Radeon Pro WX 5100, which I may want to 
experiment with later if I can find a way to extract the sound from my 
DisplayPort link (not HDMI after all; I was mistaken about that in an earlier 
thread). I can't disable it anyway, as far as I know. It may account for the 
Intel modules.

Third, I haven't any alsa packages installed, except for alsamixer which I 
installed to help with this problem (it didn't). There's no starting or 
stopping alsa; KDE seems to have what it needs without alsa specifically. 
That's why I had no asound.conf; it's also why I rebooted instead of doing 
something less heavy handed. Then again, why do I need an asound.conf?

-- 
Regards,
Peter.