Hi, all!

I have an Intel integrated audio card on my Gentoo laptop.
lspci | grep Audio
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01)

I am able to use it to play music but unable to use the microphone for input.

I am using alsa sound system but my item: mic in alsamixer is empty. I can't set the mic at all.

emerge --info
Portage 2.1.6.7 (default/linux/x86/2008.0, gcc-4.1.2, glibc-2.8_p20080602-r1, 2.6.27-gentoo-r10 i686)
================================================== ===============
System uname: Linux-2.6.27-gentoo-r10-i686-Intel-R-_Core-TM-2_CPU_T5600_@_1.83GHz-with-glibc2.0
Timestamp of tree: Wed, 15 Apr 2009 18:05:01 +0000
app-shells/bash: 3.2_p39
dev-java/java-config: 1.3.7-r1, 2.1.7
dev-lang/python: 2.4.4-r13, 2.5.2-r7
dev-python/pycrypto: 2.0.1-r6
dev-util/cmake: 2.6.2-r1
sys-apps/baselayout: 1.12.11.1
sys-apps/sandbox: 1.2.18.1-r2
sys-devel/autoconf: 2.13, 2.63
sys-devel/automake: 1.5, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10.2
sys-devel/binutils: 2.18-r3
sys-devel/gcc-config: 1.4.0-r4
sys-devel/libtool: 1.5.26
virtual/os-headers: 2.6.27-r2
ACCEPT_KEYWORDS="x86"
CBUILD="i686-pc-linux-gnu"
CFLAGS="-O2 -march=i686 -pipe"
CHOST="i686-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/share/config /var/lib/hsqldb"
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/revdep-rebuild /etc/terminfo /etc/udev/rules.d"
CXXFLAGS="-O2 -march=i686 -pipe"
DISTDIR="/usr/portage/distfiles"
FEATURES="distlocks fixpackages parallel-fetch protect-owned sandbox sfperms strict unmerge-orphans userfetch"
GENTOO_MIRRORS="http://distfiles.gentoo.org http://distro.ibiblio.org/pub/linux/distributions/gentoo"
LANG="en_US.UTF-8"
LDFLAGS="-Wl,-O1"
PKGDIR="/usr/portage/packages"
PORTAGE_CONFIGROOT="/"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="X acl alsa arts berkdb bzip2 cairo cdr cli cracklib crypt cups dbus dri dvd dvdr fortran gdbm gnome gpm gtk hal iconv ipv6 isdnlog java jpeg kde midi mp3 mudflap ncurses nls nptl nptlonly opengl openmp pam pcre perl portaudio pppd python qt3 qt4 readline reflection session spl ssl sysfs tcpd tiff udf unicode x86 xorg xulrunner zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1 emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" ELIBC="glibc" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" USERLAND="GNU" VIDEO_CARDS="fbdev glint i810 intel mach64 mga neomagic nv r128 radeon savage sis tdfx trident vesa vga via vmware voodoo"
Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, FFLAGS, INSTALL_MASK, LC_ALL, LINGUAS, MAKEOPTS, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, PORTDIR_OVERLAY

The only solution to make microphone work is to install linux-backports-modules-alsa-generic...

Just go to:

Menu / System / Administration / Synaptic Package Manager

And search and mark for installation:

linux-backports-modules-alsa-generic

tip: if you have multiple versions click on the first and read the description which should inform what name to install...

If after the reboot and mic mute is off, still does not work, just go to terminal and type:

sudo nano /etc/modprobe.d/alsa-base.conf

and add or change the following:

options snd-hda-intel model=auto enable=yes

Then Ctrl+X, type Y to write and exit, reboot and mic will work.

Bye and have lots of fun with Ubuntu (the best).