Arch Linux

s4ms3milia

Member

Registered: 2012-01-16

Posts: 24

Freezes when using i915 rc6 = 1

Hi,

my laptop is a thinkpad x220i. Increasing the battery life by almost 100% using the i915 rc6 kernel option always used to work. However roughly a month ago I started to get random freezes. When I enable the option I can sometimes get past the login screen of GDM (I use gnome-shell) but most of the time it freezes right away when GDM is loaded.

I searched for a hint in the log files but didn't find anything suspicious. (no gpu hung errors or something like that)
I also tried the LTS kernel with the same results.

Other options like lvds downlock or frame buffer compression work just fine.

When the system freezes I have to cold reboot, I can't switch to another tty and can't move the mouse.

With this xorg.conf I can boot, however I only get into gnome-fallback.

/etc/X11/xorg.conf.d/20-intel.conf

 Section "Device"
    Identifier "old intel stuff"
    Driver "intel"
    Option "Shadow" "True"
    Option "DRI" "false"
 EndSection

Any ideas how to debug this or maybe even a fix?

65kid

Member

From: Germany

Registered: 2011-01-26

Posts: 663

Re: Freezes when using i915 rc6 = 1

These kind of crashes are actually the reason rc6 isn't enabled by default. Afaik most rc6 crashes are somehow related to VT-d, disabling it in your BIOS might fix it. rc6 will be enabled by default in kernel 3.4, so you might also want to try linux-mainline from the AUR.

steffinger

Member

From: Munich/Beijing

Registered: 2011-02-07

Posts: 41

Re: Freezes when using i915 rc6 = 1

I got similar crashes. Most of the time the system runs fine, but for about one month now it tends to crash with some hardware accelerated webelements or desktop applications. I know it can be fixed with 3.4, but i'd really love to see some debug messages, because as s4ms3milia said there is nothing in the logs. So any ideas how to debug this?

cfr

Member

From: Cymru

Registered: 2011-11-27

Posts: 7,178

Re: Freezes when using i915 rc6 = 1

You could try enabling the "magic SysRq key" and getting debug info that way. (I've sometimes managed to get some this way when the logs were a blank.)

What's "VT-d"?

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s4ms3milia

Member

Registered: 2012-01-16

Posts: 24

Re: Freezes when using i915 rc6 = 1

I already used the Kernel option intel_iommu=off, my guess was that it does the same as disabling those things in the BIOS.

However I am right now compiling the mainline kernel and when I reboot I will also disable VT-d in the BIOS.

Man I hope I can enable that shit now, my fan is going nuts als the time and the battery runtime is a pain in the ass during classes.

Mhh I can't get the mainline Kernel to boot. All I get is "waiting 10 seconds for dev/sdxx", at first I thought it was because of dev-by-uuid but specifying dev/sdxx explicitly didn't help.

Last edited by s4ms3milia (2012-05-09 10:51:06)

s4ms3milia

Member

Registered: 2012-01-16

Posts: 24

Re: Freezes when using i915 rc6 = 1

Ok, I did now test the current mainline kernel aswell. Same result. 15 seconds after logging in: freeze.

I disabled Intels virtualizations stuff in the bios.

Default Kernel with rc6: freeze
LTS-Kernel with rc6: freeze
Mainline-Kernel with rc6: freeze

That sucks

Last edited by s4ms3milia (2012-05-10 13:14:00)

steffinger

Member

From: Munich/Beijing

Registered: 2011-02-07

Posts: 41

Re: Freezes when using i915 rc6 = 1

You could try enabling the "magic SysRq key" and getting debug info that way. (I've sometimes managed to get some this way when the logs were a blank.)

My problems seem to be much easier then those you have, s4ms3milia. I had another freeze after two calm weeks. I tried the "magic SysRq key" cfr suggested, but my logs stayed blank. I'm kind of giving up as kernel 3.4 is around the corner, which promises better rc6 support.

Last edited by steffinger (2012-05-24 09:46:20)

s4ms3milia

Member

Registered: 2012-01-16

Posts: 24

Re: Freezes when using i915 rc6 = 1

Now 3.4 is there, rc6 is enabled by default and I am still getting those freezes

rvdli

Member

Registered: 2011-08-25

Posts: 27

Re: Freezes when using i915 rc6 = 1

I have those freezes on my laptop (Sandy Bridge i7) even when I'm not using rc6. And I still didn't find what can be causing this.
I already tried enabling and disabling rc6, the stable 3.4, pcie_aspm=force...