Quote Originally Posted by -iy- View Post
Hi All

I have a Dell Vostro 3350 laptop with i7 processor and AMD 6470M graphics card (dynamic switchable). I had problems with graphics. It caused crashes of system. Now laptop works, I hope. Only AMD card can not be used. Dynamic switchable cards don't work under linux at all now (https://bbs.archlinux.org/viewtopic.php?id=120622)

After installation of xubuntu 11.04, random crashes occured on boot (on load of radeon driver). I use radeon open source driver. This was solved by instalation of new 3.0.0 kernel from oneiric. I followed this instructions:


Additionaly I upgraded xserver-xorg-video-radeon package, but it probably is not necessary.

The 3.0.0 kernel have increased power consumption. But in can be improved by ading kernel atributtes.

In /etc/default/grub change


 GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=force i915.i915_enable_rc6=1"
(Based on https://bugzilla.redhat.com/show_bug.cgi?id=727579 )

AMD card is powered in default. But can be turned off by switcharoo. I added this lines into /etc/rc.local
while ! [ -e /sys/kernel/debug/vgaswitcheroo/switch ];
    echo "hack: Trying to load radeon driver"
    modprobe radeon
    sleep 1

eecho ON > /sys/kernel/debug/vgaswitcheroo/switch
echo IGD > /sys/kernel/debug/vgaswitcheroo/switch
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
It is based on:


But then another problem occured. After suspend/resume, AMD card was powered and any attempt to turn it off caused crash. What more the
cat /sys/kernel/debug/vgaswitcheroo/switch
showed that AMD card is off, fan was not running, but power consumption was 10W above normal. I have found a workaround. With this workaround power constupmtion stays normal after suspend/resume.

Workaround is simple: Turn ON AMD card during suspend.

create script:

case "$1" in
	echo "radeon: powering on"
        echo ON > /sys/kernel/debug/vgaswitcheroo/switch
	echo "radeon: powering off"
        echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
Now AMD card do not cause any problems. Only, it can't not be used :{.
Thank you so much. Your beautiful sleep script finally fixed the last of my problems with the discrete graphics.

I had a script that did echo ON and an echo OFF on resume which lead to a black screen. This however works perfectly.

You just saved me hours, I can finally go to sleep