[PATCH] mm: Work around Intel SNB GTT bug with some physical pages.

[Andi Kleen]

Stéphane Marchesin <marcheu at chromium.org> writes:

> While investing some Sandy Bridge rendering corruption, I found out
> that all physical memory pages below 1MiB were returning garbage when
> read through the GTT. This has been causing graphics corruption (when
> it's used for textures, render targets and pixmaps) and GPU hangups
> (when it's used for GPU batch buffers).

It would be possible to exlude GFP_DMA from the page allocator. That
covers the first 16MB. You just need a custom zone list with ZONE_DMA.

-Andi

-- 
ak at linux.intel.com -- Speaking for myself only