Re: [PATCH] drm/xe: put COMMON_SLICE_CHICKEN3 on the allowlist for UMD

[Gustavo Sousa <gustavo.sousa@intel.com>]

Quoting Lionel Landwerlin (2026-01-05 12:02:22-03:00)
>Similar to i915's commit cebc13de7e704b1355bea208a9f9cdb042c74588
>("drm/i915: Whitelist COMMON_SLICE_CHICKEN3 for UMD access")
>
>A recommended tuning setting for both gen12 and Xe_HP platforms
>requires that we grant userspace r/w access to the
>COMMON_SLICE_CHICKEN3 register.
>
>Bspec: 73993, 73994, 31870, 68331
>Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
>---
> drivers/gpu/drm/xe/xe_reg_whitelist.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
>diff --git a/drivers/gpu/drm/xe/xe_reg_whitelist.c b/drivers/gpu/drm/xe/xe_reg_whitelist.c
>index 1391cb6ec9c62..4dcbc42574bf5 100644
>--- a/drivers/gpu/drm/xe/xe_reg_whitelist.c
>+++ b/drivers/gpu/drm/xe/xe_reg_whitelist.c
>@@ -45,6 +45,11 @@ static const struct xe_rtp_entry_sr register_whitelist[] = {
>           XE_RTP_RULES(GRAPHICS_VERSION_RANGE(1200, 1210), ENGINE_CLASS(RENDER)),
>           XE_RTP_ACTIONS(WHITELIST(COMMON_SLICE_CHICKEN1, 0))
>         },
>+        { XE_RTP_NAME("allow_common_slice_chicken3"),
>+          XE_RTP_RULES(GRAPHICS_VERSION_RANGE(1200, XE_RTP_END_VERSION_UNDEFINED),

With XE_RTP_END_VERSION_UNDEFINED, this spans to any current and future
GT containig graphics version 12 or higher.  I believe we need to limit
this to 12.74.

--
Gustavo Sousa

>+                       ENGINE_CLASS(RENDER)),
>+          XE_RTP_ACTIONS(WHITELIST(COMMON_SLICE_CHICKEN3, 0))
>+        },
>         { XE_RTP_NAME("1806527549"),
>           XE_RTP_RULES(GRAPHICS_VERSION_RANGE(1200, 1210), ENGINE_CLASS(RENDER)),
>           XE_RTP_ACTIONS(WHITELIST(HIZ_CHICKEN, 0))
>-- 
>2.43.0
>