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

Andi Kleen
2003-05-15T15:09:20Z

On Thu, May 15, 2003 at 05:16:33PM +0200, Dave Jones wrote:
> 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.

To make all 0.001 users left of them happy yes. I think the patch should
be applied anyways.

-Andi