Re: [Intel-gfx] [PATCH V2 3/3] drm/i915: Refine VT-d scanout workaround

2021-12-03 Thread Ramalingam C
On 2021-12-02 at 14:54:24 +0530, Tejas Upadhyay wrote: > From: Chris Wilson > > VT-d may cause overfetch of the scanout PTE, both before and after the > vma (depending on the scanout orientation). bspec recommends that we > provide a tile-row in either directions, and suggests using 168 PTE, >

[Intel-gfx] [PATCH V2 3/3] drm/i915: Refine VT-d scanout workaround

2021-12-02 Thread Tejas Upadhyay
From: Chris Wilson VT-d may cause overfetch of the scanout PTE, both before and after the vma (depending on the scanout orientation). bspec recommends that we provide a tile-row in either directions, and suggests using 168 PTE, warning that the accesses will wrap around the ends of the GGTT.