My system has hybrid (and I believe muxless,i.e. only the integrated card is actually connected to the display) graphics. The first card is an Intel HD 4400
, and the second card is the AMD Radeon HD 8670M
(solar system series, not OLAND). Thus, currently the open-source radeon
driver does not support the card, and I am forced to use the proprietary fglrx
driver.
Why not just turn the dGPU card off without fglrx?
I have no need of fancy graphics and would be happy to simply turn the discrete ATI card off, so long as it was properly switched off and was not overheating/eating battery. The options to do this without fglrx
and pxpress
seemed limited to me: I have no vgaswitcheroo
switch (even before fglrx
was ever installed) and I can only deduce this was because the radeon
driver does not yet support my card/does not properly load it yet, see my question here for more on that and the things I tried. Other methods like acpi_call
have been reported as at best "proof of concept" and at worst dangerous, so I'd rather not venture into using them. More reliable projects like bumbleebee
are nividia only.
Simply leave the AMD card driverless
Relying on just the i915
intel driver works flawlessly, no bugs, no problems, however the AMD card is then left UNCLAIMED and could possibly lead to overheating/battery drain, so I am not so happy about that.
Ubuntu 12.04 LTS with fglrx
I started here, and experienced a bug when the iGPU
was selected. This bug manifests itself whenever the screen is locked, the laptop lid is closed, or even when the computer is left inactive with something like xscreensaver
installed instead with no lockscreen enabled. It causes a black screen with a moveable cursor only; switching tty and back does not recover, and a restart from the tty is needed. It does not happen every single time but happens pretty regularly, at least once or twice day. All saved work is lost.
I tried both the fglrx
in the repos, and the latest 13.10 from the AMD website. No change.
When the dGPU is selected instead (from the AMD Catalyst control centre, or ultimately by pxpress) this bug does not occur, but I had another bug which I won't bother getting into here.
Ubuntu 13.10 with fglrx
A very similar bug here but not quite as severe. Exactly the same conditions, namely lockscreen, lidclose, inactivity (if xscreensaver is being used). This time the frozen screen is not black, but a picture of your desktop at the moment of the freeze, again with moveable cursor. Here I only tried the latest fglrx AMD drivers 13.10.
Again no problems with just the i915
driver (no fglrx
) and again no problems with dGPU
selected.
Some things I tried:
1) Disabling vsync
. I tried this both in compiz settings manager, and by aticonfig --sync-vsync=off
followed by reboot. No change.
2) Turning DPMS off. Option "DPMS" "false"
in the xorg.conf
monitor stanza. (Of course, I also changing gnome settings "Do Nothing/Don't suspend" for battery and AC too).No change.
3) Option "AIGLX" "off"
in server flags of xorg.conf
. No change.
4) Modifying the atieventsd
so it worked properly for Ubuntu, see my post here. And also, running without it. No change.
5) Booting with the options
Option "Capabilities" "0x00000800"
Option "KernelModuleParm" "locked-userpages=0"
Option "NoAccel" "True"
in the xorg.conf
Device stanza. No change.
6) Booting with nomodeset
as kernel parameter. No change.
7) Turning off acpi
interaction from aticonfig
:
--acpi-services=off
--acpi-display-switch=off
No change.
Why does it work with just intel?
One thing I don't understand is why it works with the just the intel i915
driver. I thought pxpress
would just hand over control to that driver on bootup, so if it worked with the i915
alone, I'd have expected it to work with pxpress selecting igpu
.
I know fglrx
installs its own libGl implemenation also, but it switches back to the old stock MESA libGL implementation when the intel card is selected (c.f. /usr/lib/fglrx/switchlibGL
python script).
So when igpu
selected, it should be exactly equivalent to life before fglrx
after a reboot?