> Subject: [PATCH v2] drm/{i915, xe}/display: add core workaround query to
> display parent interface
>
> There are workarounds display needs to apply depending on information only
> available to the core driver. Add a display parent interface for the query.
> For
> starters, there's only one workaround like this, so keep it simple instead of
> over-engineering.
>
> This lets us drop an #ifdef I915 as well as xe dependency on some display
> headers.
>
> v2: git add xe_display_wa.h
>
> Signed-off-by: Jani Nikula <[email protected]>
> ---
> drivers/gpu/drm/i915/display/intel_display_wa.c | 3 ++-
> drivers/gpu/drm/i915/display/intel_display_wa.h | 9 ---------
> drivers/gpu/drm/xe/display/xe_display.c | 2 ++
> drivers/gpu/drm/xe/display/xe_display_wa.c | 13 +++++++++----
> drivers/gpu/drm/xe/display/xe_display_wa.h | 9 +++++++++
> include/drm/intel/display_parent_interface.h | 7 +++++++
> 6 files changed, 29 insertions(+), 14 deletions(-) create mode 100644
> drivers/gpu/drm/xe/display/xe_display_wa.h
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_wa.c
> b/drivers/gpu/drm/i915/display/intel_display_wa.c
> index 3662e0f17c69..10dc2930468d 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_wa.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_wa.c
> @@ -4,6 +4,7 @@
> */
>
> #include <drm/drm_print.h>
> +#include <drm/intel/display_parent_interface.h>
> #include <drm/intel/step.h>
>
> #include "intel_de.h"
> @@ -131,7 +132,7 @@ bool __intel_display_wa(struct intel_display *display,
> enum intel_display_wa wa,
> case INTEL_DISPLAY_WA_16011863758:
> return DISPLAY_VER(display) >= 11;
> case INTEL_DISPLAY_WA_16023588340:
> - return intel_display_needs_wa_16023588340(display);
> + return display->parent->wa &&
> +display->parent->wa->wa_16023588340(display->drm);
> case INTEL_DISPLAY_WA_16025573575:
> return intel_display_needs_wa_16025573575(display);
> case INTEL_DISPLAY_WA_16025596647:
> diff --git a/drivers/gpu/drm/i915/display/intel_display_wa.h
> b/drivers/gpu/drm/i915/display/intel_display_wa.h
> index 338b32e4162d..425a300840aa 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_wa.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_wa.h
> @@ -12,15 +12,6 @@ struct intel_display;
>
> void intel_display_wa_apply(struct intel_display *display);
>
> -#ifdef I915
> -static inline bool intel_display_needs_wa_16023588340(struct intel_display
> *display) -{
> - return false;
> -}
> -#else
> -bool intel_display_needs_wa_16023588340(struct intel_display *display); -
> #endif
> -
> /*
> * This enum lists display workarounds; each entry here must have a
> * corresponding case in __intel_display_wa(). Keep both sorted by lineage
> diff --git a/drivers/gpu/drm/xe/display/xe_display.c
> b/drivers/gpu/drm/xe/display/xe_display.c
> index 8da4c457a4a0..10d80dc812bc 100644
> --- a/drivers/gpu/drm/xe/display/xe_display.c
> +++ b/drivers/gpu/drm/xe/display/xe_display.c
> @@ -37,6 +37,7 @@
> #include "xe_display_bo.h"
> #include "xe_display_pcode.h"
> #include "xe_display_rpm.h"
> +#include "xe_display_wa.h"
> #include "xe_dsb_buffer.h"
> #include "xe_fb_pin.h"
> #include "xe_frontbuffer.h"
> @@ -458,6 +459,7 @@ static const struct intel_display_parent_interface parent
> = {
> .pcode = &xe_display_pcode_interface,
> .rpm = &xe_display_rpm_interface,
> .stolen = &xe_display_stolen_interface,
> + .wa = &xe_display_wa_interface,
Should we maybe have a comment documenting when it is okay to use this,
basically use this only if unavoidable and when
Required info is available in only core driver to avoid it being misused in
future.
Otherwise,
LGTM,
Reviewed-by: Suraj Kandpal <[email protected]>
> .has_auxccs = has_auxccs,
> };
>
> diff --git a/drivers/gpu/drm/xe/display/xe_display_wa.c
> b/drivers/gpu/drm/xe/display/xe_display_wa.c
> index 2aa1b8c03411..46e41e8a3304 100644
> --- a/drivers/gpu/drm/xe/display/xe_display_wa.c
> +++ b/drivers/gpu/drm/xe/display/xe_display_wa.c
> @@ -3,17 +3,22 @@
> * Copyright © 2024 Intel Corporation
> */
>
> -#include "intel_display_core.h"
> -#include "intel_display_wa.h"
> +#include <drm/intel/display_parent_interface.h>
> +
> #include "xe_device.h"
> +#include "xe_display_wa.h"
> #include "xe_wa.h"
>
> #include <generated/xe_wa_oob.h>
>
> -bool intel_display_needs_wa_16023588340(struct intel_display *display)
> +static bool intel_display_needs_wa_16023588340(struct drm_device *drm)
> {
> - struct xe_device *xe = to_xe_device(display->drm);
> + struct xe_device *xe = to_xe_device(drm);
> struct xe_gt *wa_gt = xe_root_mmio_gt(xe);
>
> return wa_gt && XE_GT_WA(wa_gt, 16023588340); }
> +
> +const struct intel_display_wa_interface xe_display_wa_interface = {
> + .wa_16023588340 = intel_display_needs_wa_16023588340,
> +};
> diff --git a/drivers/gpu/drm/xe/display/xe_display_wa.h
> b/drivers/gpu/drm/xe/display/xe_display_wa.h
> new file mode 100644
> index 000000000000..0262b463916d
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/display/xe_display_wa.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: MIT */
> +/* Copyright © 2026 Intel Corporation */
> +
> +#ifndef __XE_DISPLAY_WA_H__
> +#define __XE_DISPLAY_WA_H__
> +
> +extern const struct intel_display_wa_interface xe_display_wa_interface;
> +
> +#endif
> diff --git a/include/drm/intel/display_parent_interface.h
> b/include/drm/intel/display_parent_interface.h
> index de395df9ca30..bdc9f9ad4fcb 100644
> --- a/include/drm/intel/display_parent_interface.h
> +++ b/include/drm/intel/display_parent_interface.h
> @@ -230,6 +230,10 @@ struct intel_display_vlv_iosf_interface {
> int (*write)(struct drm_device *drm, enum vlv_iosf_sb_unit unit, u32
> addr, u32 val); };
>
> +struct intel_display_wa_interface {
> + bool (*wa_16023588340)(struct drm_device *drm); };
> +
> /**
> * struct intel_display_parent_interface - services parent driver provides to
> display
> *
> @@ -291,6 +295,9 @@ struct intel_display_parent_interface {
> /** @vlv_iosf: VLV IOSF sideband. Optional. */
> const struct intel_display_vlv_iosf_interface *vlv_iosf;
>
> + /** @wa: Display workarounds query. Optional. */
> + const struct intel_display_wa_interface *wa;
> +
> /* Generic independent functions */
> struct {
> /** @fence_priority_display: Set display priority. Optional. */
> --
> 2.47.3
