Re: [gentoo-user] I think I messed up USE flag by using -alsa as Gnome has no sound

[Holly Bostick]

Richard Watson schreef:
>>>Have you loaded the newly-compiled alsa driver modules for your sound
>>>card, run alsaconf and unmuted the mixer via alsamixer?
>>>Holly
>
>
> Hi again - I tried
> # emerge -s alsa
> and got loads of output. Would you know what the correct emerge command is
> for the alsa driver modules? Does alsaconf come as part of the driver
> install?

If you are using a 2.6-series kernel, the alsa drivers are part of your
*kernel* config, and no additional driver package is necessary to emerge
(although some people like to, but that's another story).

Alsaconf is part of the alsa-utils package. If you are using the
kernel's alsa drivers (which are perfectly adequate), you probably want
to emerge all the other packages that are *not* alsa-driver in order to
get everything working properly under all circumstances:

alsa-lib (required)

alsa-headers (probably required)

alsa-utils (required)

alsa-tools (required)

alsa-oss (probably optional)

alsa-firmware (probably optional)

You might also want a systray applet for the mixer if you're using KDE
or GNOME:

kamix

gamix

>
> I had installed alsamixer (with -alsa ...) earlier and it loads a blank
> interface with no controls at all.
>
> At this stage I'm doing
> # emerge --update --ask --deep --verbose --newuse --tree world
> as setting alsa on is asking quite few items to want to recompile.


OK, stop where you are. Hands off the 'Enter' key ;-) .

First, you need to confirm your kernel config. I'm going to assume that
we're going for a standard setup with the kernel modules compiled into
the kernel, rather than as loadable nodules.

Let's look at the output of

lsmod

and see what modules are already loaded. You're looking for items that
start with

snd-

and also items that contain

i810

But don't worry if you don't see them; statically compiled kernel
drivers don't show in this list anyway. But it's a pre-check before we
check the kernel itself. Now, you could look at the .config file in a
text editor, but ... spare me. Especially if you're a genkernel user,
that's even more confusing to figure out. Since I don't know if you are
in fact a genkernel user, and I furthermore don't know a thing about
genkernel (meaning, I don't know squat about initrds), we're just going
to look at the kernel the way I know how to do it

cd /usr/src/linux

make menuconfig

NOTE: if you are a genkernel user, you can (apparently) also do
genkernel --menuconfig

for the same effect, and then you'll still get a new initrd if you make
changes (and save them).

OK, now that we're in the menuconfig, we want to know the following:

1. Is support for the onboard components of your motherboard compiled
into the kernel (I am assuming that the soundcard is enabled in your
BIOS, which is necessary for it to work at all)?

2. Is support for a) sound, b) ALSA and c)ALSA OSS emulation available,
and if so, as a module or statically?

3. Are the drivers for your particular sound card compiled, and if so,
statically or as a module?

So check these settings:

Device Drivers=>ATA/ATAPI/MFM/RLL support=> AMD and nVidia IDE support


Device Drivers=>Character Devices=>NVIDIA nForce/nForce2 chipset support


(these are both to add support for what is *supposed* to be
'other'motherboard resources than onboard sound, but-- since I don't
know how motherboards are wired, thus 'what is really connected to
what'-- I tend to feel that one wants to confirm any and all 'special'
drivers for one's mobo chipset. Besides which, next after sound is all
straightened out, you may well want to configure support for 3D hardware
accelleration for your video card, in which case you'll be happy to
already know whether your mobo's agp support is active or not :-) ).

But these are the important ones to check:

Device Drivers=>Sound=> Sound card support

Device Drivers=>Sound=>ALSA=> Advanced Linux Sound Architecture

Device Drivers=>Sound=>ALSA=> Sequencer support

Device Drivers=>Sound=>ALSA=> OSS Mixer API


Device Drivers=>Sound=>ALSA=> OSS PCM (digital audio) API

Device Drivers=>Sound=>ALSA=> OSS Sequencer API

Device Drivers=>Sound=>ALSA=>PCI devices=>Intel/SiS/nVidia/AMD/ALi AC97
Controller

These are the 'necessary drivers' for your sound card, and the ALSA/ALSA
OSS emulation backend.

We can argue for a month as to whether these should be compiled as
modules or statically, but I have found with both onboard sound and an
external sound card that the following config offers the least issues
(* = static, M = module):

Sound card support M

ALSA * (however, if you want to use the alsa-driver package, this *must*
be M, or the emerge will fail)

Sequencer support M

OSS Mixer API M

OSS PCM M

OSS Sequencer * (no choice)

Actual card driver M

If any of these are missing, you'll have to select them, recompile the
kernel and reboot to the recompiled kernel.

Your problems may already be solved, if you have previously set up
alsasound and the like, but the drivers could not be found to load
anything. In which case, have fun!

If it still doesn't work, we can then move on to Part 2: setting up Alsa
on the system (as opposed to setting it up in the kernel).

And don't worry-- it's kind of a pain, but you pretty much only have to
do all this work once.

HTH,
Holly

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