Re: [PATCH] Use MTRRs by default for vesafb on x86-64

Dave Jones
2003-05-15T15:03:05Z

On Thu, May 15, 2003 at 04:56:40PM +0200, Andi Kleen wrote:

> x86-64 cannot call the 32bit VESA BIOS. This means when vesafb is active
> it does software copying in the vesa frame buffer. This is insanely slow
> when the frame buffer is not marked for write combining.
>
> Some discussion showed that the use_mtrr flag was only off for some
> old broken ET4000 ISA card. x86-64 has no ISA, so this is no concern.
> Make the default depend on CONFIG_ISA.

There are PCI ET4000's too. Though if we can get the PCI IDs for those,
we can work around them with a quirk. I have one *somewhere*, but it'll
take me a while to dig it out.

Dave