Re: [Mesa-dev] [PATCH 05/10] i965: Use Global GTT for Sandybridge post-sync non-zero workaround.

2014-01-14 Thread Daniel Vetter
On Mon, Jan 13, 2014 at 01:02:19PM -0800, Eric Anholt wrote: > Kenneth Graunke writes: > > > On 01/09/2014 10:03 PM, Eric Anholt wrote: > >> Eric Anholt writes: > >> > >>> Kenneth Graunke writes: > >>> > The kernel doesn't even set up the aliasing PPGTT on Sandybridge, so any > write

Re: [Mesa-dev] [PATCH 05/10] i965: Use Global GTT for Sandybridge post-sync non-zero workaround.

2014-01-13 Thread Eric Anholt
Kenneth Graunke writes: > On 01/09/2014 10:03 PM, Eric Anholt wrote: >> Eric Anholt writes: >> >>> Kenneth Graunke writes: >>> The kernel doesn't even set up the aliasing PPGTT on Sandybridge, so any writes marked as PPGTT will likely just get dropped on the floor. >>> >>> The hardwa

Re: [Mesa-dev] [PATCH 05/10] i965: Use Global GTT for Sandybridge post-sync non-zero workaround.

2014-01-10 Thread Kenneth Graunke
On 01/09/2014 10:03 PM, Eric Anholt wrote: > Eric Anholt writes: > >> Kenneth Graunke writes: >> >>> The kernel doesn't even set up the aliasing PPGTT on Sandybridge, so any >>> writes marked as PPGTT will likely just get dropped on the floor. >> >> The hardware bug is that writes not marked as

Re: [Mesa-dev] [PATCH 05/10] i965: Use Global GTT for Sandybridge post-sync non-zero workaround.

2014-01-09 Thread Eric Anholt
Eric Anholt writes: > Kenneth Graunke writes: > >> The kernel doesn't even set up the aliasing PPGTT on Sandybridge, so any >> writes marked as PPGTT will likely just get dropped on the floor. > > The hardware bug is that writes not marked as GTT are still looked up in > the GTT anyway. > > The

Re: [Mesa-dev] [PATCH 05/10] i965: Use Global GTT for Sandybridge post-sync non-zero workaround.

2014-01-09 Thread Eric Anholt
Kenneth Graunke writes: > The kernel doesn't even set up the aliasing PPGTT on Sandybridge, so any > writes marked as PPGTT will likely just get dropped on the floor. The hardware bug is that writes not marked as GTT are still looked up in the GTT anyway. The kernel does set up the PPGTT, which

Re: [Mesa-dev] [PATCH 05/10] i965: Use Global GTT for Sandybridge post-sync non-zero workaround.

2013-12-13 Thread Daniel Vetter
On Thu, Dec 12, 2013 at 01:26:37AM -0800, Kenneth Graunke wrote: > The kernel doesn't even set up the aliasing PPGTT on Sandybridge, so any > writes marked as PPGTT will likely just get dropped on the floor. Ermh, aliasing ppgtt is enabled on snb. But the CS write stuff is broken and will always l

[Mesa-dev] [PATCH 05/10] i965: Use Global GTT for Sandybridge post-sync non-zero workaround.

2013-12-12 Thread Kenneth Graunke
The kernel doesn't even set up the aliasing PPGTT on Sandybridge, so any writes marked as PPGTT will likely just get dropped on the floor. This begs the question: is the simple act of /requesting/ a write good enough for the workaround, or does it need to actually work? Past experience suggests t