[Bug 627163] [NEW] KMS refuses to detect second head on i945 chipset

[Brad Campbell]

Public bug reported:

I have a 2006 vintage Mac Mini. With a splitter cable I can get simultaneous VGA & DVI outputs and run in dual head mode.
In X with 10.04 as shipped it will prefer the VGA monitor. If I unplug the VGA monitor the DVI monitor springs to life. If I re-plug the VGA monitor the DVI monitor switches off and the desktop comes back up on the VGA monitor.

I can work around the issue by disabling kernel modesetting by adding "i915.modeset=0" to the kernel command line.
I then had to manually construct /etc/X11/xorg.conf with appropriate modelines as the DDC detection failed to detect anything greater than 1366x768 on either monitor (one is 1920x1200 and the other is 1600x1200).

It occurs to me that this bug report is going to contain the latest
Maverick test kernel. I installed that as a test to see if it might be
fixed (which it's not), but by default I use the standard i386 10.04
kernel.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: linux-image (not installed)
Regression: No
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.35-19.28-generic 2.6.35.3
Uname: Linux 2.6.35-19-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: i386
AudioDevicesInUse:
 USER        PID ACCESS COMMAND
 /dev/snd/controlC0:  brad       2276 F.... pulseaudio
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0x90440000 irq 43'
   Mixer name	: 'SigmaTel STAC9221 A1'
   Components	: 'HDA:83847680,106b0800,00103401'
   Controls      : 19
   Simple ctrls  : 11
Date: Tue Aug 31 08:28:45 2010
IwConfig:
 lo        no wireless extensions.
 
 eth0      no wireless extensions.
 
 tap0      no wireless extensions.
MachineType: Apple Computer, Inc. Macmini1,1
ProcCmdLine: root=UUID=2c80d27c-9036-4184-bb9c-f8eda9fb5463 ro quiet splash i915.modeset=0
ProcEnviron:
 LANGUAGE=en_AU:en
 PATH=(custom, user)
 LANG=en_AU.utf8
 SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.34.1
RfKill:
 
SourcePackage: linux
dmi.bios.date: 10/12/06
dmi.bios.vendor: Apple Computer, Inc.
dmi.bios.version: MM11.88Z.0055.B08.0610121326
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Mac-F4208EC8
dmi.board.vendor: Apple Computer, Inc.
dmi.board.version: PVT
dmi.chassis.asset.tag: Asset Tag
dmi.chassis.type: 4
dmi.chassis.vendor: Apple Computer, Inc.
dmi.chassis.version: Mac-F4208EC8
dmi.modalias: dmi:bvnAppleComputer,Inc.:bvrMM11.88Z.0055.B08.0610121326:bd10/12/06:svnAppleComputer,Inc.:pnMacmini1,1:pvr1.0:rvnAppleComputer,Inc.:rnMac-F4208EC8:rvrPVT:cvnAppleComputer,Inc.:ct4:cvrMac-F4208EC8:
dmi.product.name: Macmini1,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Computer, Inc.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: apport-bug graphics i386 lucid needs-upstream-testing

-- 
KMS refuses to detect second head on i945 chipset
https://bugs.launchpad.net/bugs/627163
You received this bug notification because you are a member of Kernel
Bugs, which is subscribed to linux in ubuntu.