[Intel-xe] [PATCH v6 1/5] drm/xe/pat: trim the xelp PAT table

[Lucas De Marchi]

On Thu, Sep 28, 2023 at 11:05:39AM +0100, Matthew Auld wrote:
>We don't seem to use the 4-7 pat indexes, even though they are defined
>by the HW. In the next patch userspace will be able to directly set the
>pat_index as part of vm_bind and we don't want to allow setting 4-7.
>Simplest is to just ignore them here.

But why do we want to leave them in un-programmed state? Wouldn't it be
more future-proof we we program them to something like UC?

Lucas De Marchi

>
>Suggested-by: Matt Roper <matthew.d.roper at intel.com>
>Signed-off-by: Matthew Auld <matthew.auld at intel.com>
>Cc: Pallavi Mishra <pallavi.mishra at intel.com>
>Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>Reviewed-by: Matt Roper <matthew.d.roper at intel.com>
>---
> drivers/gpu/drm/xe/xe_pat.c | 4 ----
> 1 file changed, 4 deletions(-)
>
>diff --git a/drivers/gpu/drm/xe/xe_pat.c b/drivers/gpu/drm/xe/xe_pat.c
>index 869aee64641f..36b79d675e54 100644
>--- a/drivers/gpu/drm/xe/xe_pat.c
>+++ b/drivers/gpu/drm/xe/xe_pat.c
>@@ -42,10 +42,6 @@ static const u32 xelp_pat_table[] = {
> 	[1] = XELP_PAT_WC,
> 	[2] = XELP_PAT_WT,
> 	[3] = XELP_PAT_UC,
>-	[4] = XELP_PAT_WB,
>-	[5] = XELP_PAT_WB,
>-	[6] = XELP_PAT_WB,
>-	[7] = XELP_PAT_WB,
> };
>
> static const u32 xehpc_pat_table[] = {
>-- 
>2.41.0
>