No Sound on Macbook 7,1 on uptodate Maverick installation

[Benjamin Bender]

Soundcard is recocnized - but no sound is playing. All Channels are up in alsamixer & gnome-sound-prefs. Hardware is a 13" Macbook Pro 7,1.

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: alsa-base 1.0.23+dfsg-1ubuntu4
ProcVersionSignature: Ubuntu 2.6.35-22.33-generic 2.6.35.4
Uname: Linux 2.6.35-22-generic x86_64
NonfreeKernelModules: nvidia wl
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: NVidia [HDA NVidia], device 0: Cirrus Analog [Cirrus Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: bb 18881 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'NVidia'/'HDA NVidia at 0xd3480000 irq 23'
   Mixer name : 'Nvidia MCP89 HDMI'
   Components : 'HDA:10134206,106b0d00,00100301 HDA:10de000c,10de0101,00100200'
   Controls : 28
   Simple ctrls : 12
CheckboxCommand: gst_pipeline_test -t 2 'audiotestsrc wave=sine freq=512 ! audioconvert ! audioresample ! gconfaudiosink'
CheckboxDescription:
 Klicken Sie auf »Testen«, um einen Ton über das automatisch erkannte Wiedergabe-Gerät abzuspielen.

 Do you hear a sound and was that sound free of any distortion, clicks or other strange noises?
CheckboxTest: playback_auto
Date: Sat Sep 25 11:41:39 2010
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Alpha amd64 (20100908)
PackageArchitecture: all
ProcEnviron:
 SHELL=/bin/bash
 LANG=de_DE.utf8
SourcePackage: alsa-driver
dmi.bios.date: 03/25/10
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP71.88Z.0039.B05.1003251322
dmi.board.name: Mac-F222BEC8
dmi.board.vendor: Apple Inc.
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F222BEC8
dmi.modalias: dmi:bvnAppleInc.:bvrMBP71.88Z.0039.B05.1003251322:bd03/25/10:svnAppleInc.:pnMacBookPro7,1:pvr1.0:rvnAppleInc.:rnMac-F222BEC8:rvr:cvnAppleInc.:ct10:cvrMac-F222BEC8:
dmi.product.name: MacBookPro7,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.

[Rees George (rgeorge280)]

By following the instructions under the sound section here: https://help.ubuntu.com/community/MacBookPro7-1/Lucid#Sound I was able to get sound working.

[Luke Yelavich (themuso)]

Thanks for the pointer, I'll go ahead and make that a perminent fix, i.e the module model=mbp55 step will no longer be needed for future kernel updates in natty, and possibly maverick.

[Mark Smith (tntc-tig)]

I took a look at alsamixer, and it would seem that Alsa thinks that my left speaker is actually my front speaker, and the right is another surround speaker. This is probably why audio is so quiet and distorted.

[Julian Wiedmann (jwiedmann)]

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=f46119b73425df9d1e05c5d5e909a993d95b0218
This patch should have landed in all releases by now.