2.6.12 and above create 100% CPU with xorg on iMac

(In reply to comment #0)
This same problem occured with the RC1 Breezy LiveCD on the iMac. The card is a
Ati Technologies, Inc. Rage 128 Pro Ultra (TR). The LiveCD loaded the ati driver
with the same negative results. I was able to fix the problem by changing the
driver to "r128" and putting r128 and agpgart in /etc/modules. Now the Breezy
iMac is working fine with two days to go before final. If the final Breezy will
use the same installroutine as the LiveCD, then this type of iMac (see original
report) will be configured with a non-working xorg.

> After ugrading the kernel on iMac 600Mhz running Breezy Kubuntu to 2.6.12-xxx I
> can no longer login with KDM. It takes a long time before the screen gets drawn
> and the login boxes appear. When they do, the keyboard is unresponsive. This
> happens with all the 2.6.12 builds from Ubuntu that I've tried, and also with
> the 2.6.13 official Debian kernel from www.ppckernel.org that I tested. I can
> login with ssh from another box and top shows that xorg is eating 99% CPU
> resources. Not sure if this is KDE-specific since I haven't tried loading Gnome
> on this iMac. Never any problems with 2.6.11 and below.
>
> pvz@imac:~$ cat /proc/cpuinfo
> processor : 0
> cpu : 745/755
> temperature : 19-21 C (uncalibrated)
> clock : 600MHz
> revision : 50.20 (pvr 0008 3214)
> bogomips : 1196.03
> machine : PowerMac4,1
> motherboard : PowerMac4,1 MacRISC2 MacRISC Power Macintosh
> detected as : 256 (iMac "Flower Power")
> pmac flags : 00000010
> L2 cache : 256K unified
> memory : 512MB
> pmac-generation : NewWorld

If possible, please upgrade to Dapper's 2.6.15-7 kernel. If you do not want to
upgrade to Dapper, then you can also wait for the Dapper Flight 2 CD's, which
are due out within the next few days.

Let me know if this bug still exists with this kernel.

pvz,

Do you still experience this problem? If so, can you test it with a more recent kernel, like the ones available in Dapper? Thank you.

On Thu, 2006-03-30 at 08:10 +0000, Daniel Robitaille wrote:
> Public bug report changed:
> https://launchpad.net/malone/bugs/22667
>
> Comment:
> pvz,
>
> Do you still experience this problem? If so, can you test it with a more recent kernel, like the ones available in Dapper? Thank you.

It is still there with all kernel versions up untill the latest Dapper
2.6.15-19-powerpc, and the Debian testing kernels. But the fix on my
iMac is easy: uncomment dri in xorg.conf and the problem disappears.

pvz

Pretty sure this is an Xorg bug. Removing FBDev option from /etc/X11/xorg.conf fixes the problem

Just to add a note that I experienced the same problem last week on my iMac Indigo (500 Mhz, 768 Mb RAM). I downloaded the most recent versions of Ubuntu alternate and Xubuntu alternate (the regular ones would not boot) and attempted to install them.

After installing it took a very long time for GDM to load and the screen to be drawn. After login I could move the mouse freely, but after clicking on a menu item the system froze. Only a hard reset was possible.

Debian Sarge and Debian Sid don't have the same problem. Sarge is running 2.6.8 kernel by default. I tried Yellowdog on the same box and it didn't have this problem as well. It seems to be specific to Ubuntu.

The suggested DRI and FBDev options work fine both in Yellowdog and Debian Sarge/Sid and did not have to be uncommented on my box.

Given the "I experienced the same problem last week on my iMac Indigo" comment, I think this can be called confirmed.

Can someone test this under Edgy or a Feisty build so we can see if this bug still exists?

No reply since months, closing the bug.

Please test with a gutsy test-release, and reopen if necessary.