[PATCH] drm/xe/ptl: Disable null query for anyhit shader

[Gustavo Sousa]

Quoting Nitin Gote (2025-05-07 09:44:37-03:00)
>For PTL, disable null query for anyhit shader as it
>currently does not bring any performance benefits.
>Quite the contrary, disabling the mechanism brings a
>small but consistent perf uplift.
>
>Signed-off-by: Nitin Gote <nitin.r.gote at intel.com>

This seems to match the requirements for Xe3 according to the
description of RT_CTL. So

Reviewed-by: Gustavo Sousa <gustavo.sousa at intel.com>

However, we usually have entries in Bspec 72161 for this kind of stuff.
Could we get that page updated with a proper entry for this tuning,
please?

Also, I would use "drm/xe/xe3:" in the commit subject, since this is
applicable to the Xe3 IP and not necessarily specific to the platform.

--
Gustavo Sousa

>---
> drivers/gpu/drm/xe/xe_tuning.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
>diff --git a/drivers/gpu/drm/xe/xe_tuning.c b/drivers/gpu/drm/xe/xe_tuning.c
>index 49ddbda7cdef..6f2f3428b12e 100644
>--- a/drivers/gpu/drm/xe/xe_tuning.c
>+++ b/drivers/gpu/drm/xe/xe_tuning.c
>@@ -98,6 +98,11 @@ static const struct xe_rtp_entry_sr engine_tunings[] = {
>                        ENGINE_CLASS(RENDER)),
>           XE_RTP_ACTIONS(SET(SAMPLER_MODE, INDIRECT_STATE_BASE_ADDR_OVERRIDE))
>         },
>+        { XE_RTP_NAME("Tuning: Disable NULL query for Anyhit Shader"),
>+          XE_RTP_RULES(GRAPHICS_VERSION_RANGE(3000, 3001),
>+                       FUNC(xe_rtp_match_first_render_or_compute)),
>+          XE_RTP_ACTIONS(SET(RT_CTRL, DIS_NULL_QUERY))
>+        },
> };
> 
> static const struct xe_rtp_entry_sr lrc_tunings[] = {
>-- 
>2.25.1
>