The problem is reproducible on my ACER 3820 Notebook. switching the GPU via:
# echo "DDIS" > /sys/kernel/debug/vgaswicheroo
and:
# echo "DIGD" > /sys/kernel/debug/vgaswicheroo
works fine as root user. After the next restart the active GPU is the chosen one (marked in VGA switcheroo with a + and shown by glxinfo | grep vendor). When i stop lightdm and thus the Xwindow system i can also use:
# echo "DIS" > /sys/kernel/debug/vgaswicheroo
and:
# echo "IGD" > /sys/kernel/debug/vgaswicheroo
from the shell and the GPU is changed directly and everything works fine. However, as soon as I switch the ATI (DIS) off, I start running into problems. The moment I issue the command:
# echo "ON" > /sys/kernel/debug/vgaswicheroo
the screen goes black. It doesnt matter if X is active or not. The system is not crashing, but only not displaying anything any more. When I use the echo ON command in a script and use cat /sys/kernel/debug/vgaswitcheroo before and after the the echo ON, I can see that the discrete card changes state from Off to Pwr. The "+" still marks the IGD. On the X-window system I could not really find a way to recover and had to reisub.
On the console however (lightdm stopped) I could type echo "DIS" > /sys/kernel/debug/vgaswicheroo and the screen came back. Note that echo "IGD" > /sys/kernel/debug/vgaswicheroo does not work (since vgaswicheroo seems to think that the integrated card is already connected to the screen and does nothing). I can see the same effect when having the discrete card deactivated (Off) and using DIGD under X. I assume that is uses the same routine as ON, thus causing the same problem. Once I restart X again, (blindly using sysreq+K) the display comes back with the discrete card in use. Please note that switching having the dicrete card active (and connected) and the internal one switched off (power off) does not result in problems. One can use ON and DIGD and there is no problem. I now assume that in this particular notebook powering up the ATI card does change the mux(es) to this card. However, the switcheroo program/module/whatever does not notice this change and thus cannot be recovered without switching the gpu. Unfortunately this also effects my ability to use standby since (for whatever reason) one has to switch the discrete card on before going into sleep (either via a sleep.d or a rc0.d script). My suggestion for a fix is to either set the muxes to the currently active card right after switching the inactive one to ON.
WORKAROUND: WORKAROUND: /usr/lib/pm-utils/sleep.d/95switcheroo/sleep.d :
#!/bin/sh
[ -f /sys/kernel/debug/vgaswitcheroo/switch ] || exit $NA
case "$1" in
hibernate|suspend)
echo ON > /sys/kernel/debug/vgaswitcheroo/switch
if grep -c 'IGD:+:Pwr' /sys/kernel/debug/vgaswitcheroo/switch
then
echo MIGD > /sys/kernel/debug/vgaswitcheroo/switch
fi
;;
thaw|resume)
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
;;
*) exit $NA
;;
esac
add:
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
to /etc/rc.local
ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: linux-image-3.5.0-18-generic 3.5.0-18.29
ProcVersionSignature: Ubuntu 3.5.0-18.29-generic 3.5.7
Uname: Linux 3.5.0-18-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.6.1-0ubuntu6
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: sumpfmensch 3041 F.... pulseaudio
/dev/snd/controlC0: sumpfmensch 3041 F.... pulseaudio
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Date: Sun Nov 11 18:00:21 2012
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=ec5da51a-4745-4e26-98ae-d80f0ad6a1ef
InstallationDate: Installed on 2012-11-09 (2 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
MachineType: Acer Aspire 3820
MarkForUpload: True
ProcFB:
0 radeondrmfb
1 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-18-generic root=UUID=f564200f-27de-43a6-94dd-e7b3c76f9b9f ro quiet splash vt.handoff=7
PulseList:
Error: command ['pacmd', 'list'] failed with exit code 1: Home directory /home/sumpfmensch not ours.
No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
linux-restricted-modules-3.5.0-18-generic N/A
linux-backports-modules-3.5.0-18-generic N/A
linux-firmware 1.95
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/27/2010
dmi.bios.vendor: Phoenix Technologies LTD
dmi.bios.version: V1.19
dmi.board.asset.tag: No Asset Tag
dmi.board.name: JM31_CP
dmi.board.vendor: Acer
dmi.board.version: V1.19
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.version: V1.19
dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvrV1.19:bd10/27/2010:svnAcer:pnAspire3820:pvrV1.19:rvnAcer:rnJM31_CP:rvrV1.19:cvnAcer:ct10:cvrV1.19:
dmi.product.name: Aspire 3820
dmi.product.version: V1.19
dmi.sys.vendor: Acer
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