Re: [Intel-gfx] [PATCH] drm/i915: Fill unused GGTT with scratch pages for VT-d

2016-07-12 Thread Chris Wilson
On Tue, Jul 12, 2016 at 11:50:26AM +0300, Joonas Lahtinen wrote: > On pe, 2016-06-24 at 14:07 +0100, Chris Wilson wrote: > > One of the numerous VT-d workarounds we require is that the display > > hardware reads past the end of the buffer triggering VT-d faults. This > > is acknowledged in the code

Re: [Intel-gfx] [PATCH] drm/i915: Fill unused GGTT with scratch pages for VT-d

2016-07-12 Thread Joonas Lahtinen
On pe, 2016-06-24 at 14:07 +0100, Chris Wilson wrote: > One of the numerous VT-d workarounds we require is that the display > hardware reads past the end of the buffer triggering VT-d faults. This > is acknowledged in the code as being safe "since we fill the unused > portions of the GGTT with the

Re: [Intel-gfx] [PATCH] drm/i915: Fill unused GGTT with scratch pages for VT-d

2016-07-08 Thread Chris Wilson
On Fri, Jul 08, 2016 at 03:29:30PM +0300, David Weinehall wrote: > On Fri, Jun 24, 2016 at 02:07:14PM +0100, Chris Wilson wrote: > > One of the numerous VT-d workarounds we require is that the display > > hardware reads past the end of the buffer triggering VT-d faults. This > > is acknowledged in

Re: [Intel-gfx] [PATCH] drm/i915: Fill unused GGTT with scratch pages for VT-d

2016-07-08 Thread David Weinehall
On Fri, Jun 24, 2016 at 02:07:14PM +0100, Chris Wilson wrote: > One of the numerous VT-d workarounds we require is that the display > hardware reads past the end of the buffer triggering VT-d faults. This > is acknowledged in the code as being safe "since we fill the unused > portions of the GGTT w

Re: [Intel-gfx] [PATCH] drm/i915: Fill unused GGTT with scratch pages for VT-d

2016-07-08 Thread Chris Wilson
On Fri, Jun 24, 2016 at 02:07:14PM +0100, Chris Wilson wrote: > One of the numerous VT-d workarounds we require is that the display > hardware reads past the end of the buffer triggering VT-d faults. This > is acknowledged in the code as being safe "since we fill the unused > portions of the GGTT w

[Intel-gfx] [PATCH] drm/i915: Fill unused GGTT with scratch pages for VT-d

2016-06-24 Thread Chris Wilson
One of the numerous VT-d workarounds we require is that the display hardware reads past the end of the buffer triggering VT-d faults. This is acknowledged in the code as being safe "since we fill the unused portions of the GGTT with the scratch page". Alas, that is no longer always true and so we t