Re: linux-2.6.24-rcX regression / xserver-xorg-video-intel / Q35

[Zhenyu Wang <zhen78@gmail.com>]

On 2007.12.22 01:25:16 +0100, Harald Welte wrote:
> 
> I'm running an Intel DQ35JO mainboard (Q35 chipset, Q6600 CPU) and I am
> observing a regression with linux-2.6.24-rc1 through -rc6 (linux-2.6.git as
> of today, ea67db4cdbbf7f4e74150e71da0984e25121f500).
> 
> The last working version is 2.6.24-rc1.
> 
> The system is running debian unstable (current) using
> xserver-xorg-video-intel 2.2.0-1
> 
> So what is the actual problem:
> It seems to be related to the way how the iommu/gart is used for memory
> allocation of the framebuffer memory.

There's no behavior change in intel agp module between .24-rc1 to rc6.
IOMMU shouldn't matter here, if you build x86_64 system and with
CONFIG_DMAR on, you should be already having CONFIG_DMAR_GFX_WA for you.

> 
> Xorg starts just as it should, but the lower part of the screen is
> completely gobbled.  I suppose the lower part of the screen is actually
> showing off-screen memory at some completely differnt location.

Do you have other changes except kernel? like other xorg packages, bios?

> 
> Interestingly, the mouse cursor is superimposed on top of the garbage
> (and it is not distorted).

yeah, hardware cursor uses another plane than scan buffer, it's
seperate.

Could you fire a bug to https://bugs.freedesktop.org with versions and
logs? Thanks.