I don't think this is limited to only Gentoo setup, but the sound isn't working after the installation. These are the steps I took to get my sound cards recognized by ALSA and got it working.

I use ALSA instead of PulseAudio with no particular reasonings. Some say ALSA is better or vice-versa, but I'm using it since I'm just used to.

I had a suspicion that the sound might not work after the installation. I ran alsamixer to test if my suspicion was right. Well, there was no alsamixer, so I installed media-sound/alsa-utils.# emerge --ask media-sound/alsa-utils

When alsamixer was executed, it returned the following error message as I suspected.$ alsamixer cannot open mixer: No such file or directory

The system recognizes its hardware and the driver seems to be installed but ALSA didn't see them.# lspci -k | grep -iA2 audio 00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 Azalia (Intel HDA) Subsystem: Hewlett-Packard Company SBx00 Azalia (Intel HDA) Kernel driver in use: snd_hda_intel -- 01:00.1 Audio device: NVIDIA Corporation GF106 High Definition Audio Controller (rev a1) Subsystem: eVga.com. Corp. GeForce GTS 450 Kernel driver in use: snd_hda_intel

But, ALSA didn't seem to recognize those sound cards.# cat /proc/asound/cards --- no soundcards ---

I google'd around and found that the HD-audio component consists of two parts, the driver (which I seem to have installed) and codec from the Linux Kernel site as well as some Gentoo forum posts.# dmsg | grep -i codec [ 1.626139] snd_hda_intel 0000:01:00.1: no codecs found!

Yup, I don't have codecs installed. I google'd again and found that conexant for my audio device. So, I searched that codec name in the kernel config file.# grep -i conexant /usr/src/linux/.config CONFIG_SND_HDA_CODEC_CONEXANT=n

I enabled the kernel options following by ALSA in Gentto Wiki, including SND_HDA_CODEC_CONEXANT, and rebuilt the kernel.# cd /usr/src/linux # make menuconfig # make && make modules_install # make install # shudown -r now

After the reboot, kernel version should be incremented/updated.# uname -v #3 SMP Thu Feb 13 14:46:50 EST

Codecs are now installed.# dmesg | grep -i codec [ 1.254990] snd_hda_codec_realtek hdaudioC0D0: ALC888: SKU not ready 0x411111f0 [ 1.255697] snd_hda_codec_realtek hdaudioC0D0: autoconfig for ALC888: line_outs=4 (0x14/0x15/0x16/0x17/0x0) type:line [ 1.255879] snd_hda_codec_realtek hdaudioC0D0: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 1.256057] snd_hda_codec_realtek hdaudioC0D0: hp_outs=1 (0x1b/0x0/0x0/0x0/0x0) [ 1.256231] snd_hda_codec_realtek hdaudioC0D0: mono: mono_out=0x0 [ 1.256361] snd_hda_codec_realtek hdaudioC0D0: dig-out=0x11/0x1e [ 1.256491] snd_hda_codec_realtek hdaudioC0D0: inputs: [ 1.256623] snd_hda_codec_realtek hdaudioC0D0: Front Mic=0x19 [ 1.256768] snd_hda_codec_realtek hdaudioC0D0: Rear Mic=0x18 [ 1.256863] snd_hda_codec_realtek hdaudioC0D0: Line=0x1c [ 1.514180] snd_hda_codec_generic hdaudioC1D0: autoconfig for Generic: line_outs=0 (0x0/0x0/0x0/0x0/0x0) type:line [ 1.514376] snd_hda_codec_generic hdaudioC1D0: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 1.514544] snd_hda_codec_generic hdaudioC1D0: hp_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 1.514727] snd_hda_codec_generic hdaudioC1D0: mono: mono_out=0x0 [ 1.514829] snd_hda_codec_generic hdaudioC1D0: dig-out=0x5/0x0 [ 1.514967] snd_hda_codec_generic hdaudioC1D0: inputs: [ 1.561175] snd_hda_codec_generic hdaudioC1D1: autoconfig for Generic: line_outs=0 (0x0/0x0/0x0/0x0/0x0) type:line [ 1.561370] snd_hda_codec_generic hdaudioC1D1: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 1.561554] snd_hda_codec_generic hdaudioC1D1: hp_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 1.561738] snd_hda_codec_generic hdaudioC1D1: mono: mono_out=0x0 [ 1.561833] snd_hda_codec_generic hdaudioC1D1: dig-out=0x5/0x0 [ 1.561962] snd_hda_codec_generic hdaudioC1D1: inputs: [ 1.600184] snd_hda_codec_generic hdaudioC1D2: autoconfig for Generic: line_outs=0 (0x0/0x0/0x0/0x0/0x0) type:line [ 1.600378] snd_hda_codec_generic hdaudioC1D2: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 1.600563] snd_hda_codec_generic hdaudioC1D2: hp_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 1.600745] snd_hda_codec_generic hdaudioC1D2: mono: mono_out=0x0 [ 1.600882] snd_hda_codec_generic hdaudioC1D2: dig-out=0x5/0x0 [ 1.601018] snd_hda_codec_generic hdaudioC1D2: inputs: [ 1.638124] snd_hda_codec_generic hdaudioC1D3: autoconfig for Generic: line_outs=0 (0x0/0x0/0x0/0x0/0x0) type:line [ 1.638271] snd_hda_codec_generic hdaudioC1D3: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 1.638411] snd_hda_codec_generic hdaudioC1D3: hp_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 1.638551] snd_hda_codec_generic hdaudioC1D3: mono: mono_out=0x0 [ 1.638690] snd_hda_codec_generic hdaudioC1D3: dig-out=0x5/0x0 [ 1.638822] snd_hda_codec_generic hdaudioC1D3: inputs:

/proc/asound/cards which showed "--- no soundcards ---" now shows found sound cards.# cat /proc/asound/cards 0 [SB ]: HDA-Intel - HDA ATI SB HDA ATI SB at 0xfbff4000 irq 16 1 [NVidia ]: HDA-Intel - HDA NVidia HDA NVidia at 0xfe97c000 irq 19

Yes, ALSA now sees the sound cards. I checked with alsamixer and it seems to be working fine.

When I tested with aplay, I heard a noise from my speaker! I now confirmed that the sound is working on my Gentoo.# aplay < /dev/urandom

Follow the above link to get the sound working from VirtualBox clients.

That's all!
-gibb