Re: [PATCH 1/2] drm/i915/display_wa: Add helpers to check wa

[Nautiyal, Ankit K]

On 6/30/2025 12:53 PM, Jani Nikula wrote:

On Mon, 30 Jun 2025, Ankit Nautiyal <ankit.k.nauti...@intel.com> wrote:

Introduce a generic helper to check display workarounds using an enum.

Convert Wa_16023588340 to use the new interface, simplifying WA checks
and making future additions easier.

Suggested-by: Jani Nikula <jani.nik...@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
---
  drivers/gpu/drm/i915/display/intel_display_wa.c | 13 +++++++++++++
  drivers/gpu/drm/i915/display/intel_display_wa.h |  9 +++++++++
  drivers/gpu/drm/i915/display/intel_fbc.c        |  2 +-
  3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_wa.c 
b/drivers/gpu/drm/i915/display/intel_display_wa.c
index f57280e9d041..70ba66fc7e26 100644
--- a/drivers/gpu/drm/i915/display/intel_display_wa.c
+++ b/drivers/gpu/drm/i915/display/intel_display_wa.c
@@ -39,3 +39,16 @@ void intel_display_wa_apply(struct intel_display *display)
        else if (DISPLAY_VER(display) == 11)
                gen11_display_wa_apply(display);
  }
+
+bool __intel_display_wa(struct intel_display *display, enum intel_display_wa 
wa)
+{
+       switch (wa) {
+       case INTEL_DISPLAY_WA_16023588340:
+               return intel_display_needs_wa_16023588340(display);
+       default:
+               MISSING_CASE(wa);

MISSING_CASE() is a bit of a problem for i915 and display
separation. Please let's not add more. Use drm_WARN() or something.

Sure. Will get rid of the MISSING_CASE().

+               break;
+       }
+
+       return false;
+}
diff --git a/drivers/gpu/drm/i915/display/intel_display_wa.h 
b/drivers/gpu/drm/i915/display/intel_display_wa.h
index babd9d16603d..853939ebf1ac 100644
--- a/drivers/gpu/drm/i915/display/intel_display_wa.h
+++ b/drivers/gpu/drm/i915/display/intel_display_wa.h
@@ -7,6 +7,7 @@
  #define __INTEL_DISPLAY_WA_H__

#include <linux/types.h>

+#include <i915_utils.h>

Please don't put that in the header. And shouldn't be needed anyway if
you drop the MISSING_CASE().

Alright will remove this header file.

struct intel_display; @@ -21,4 +22,12 @@ static inline bool intel_display_needs_wa_16023588340(struct intel_display *disp

  bool intel_display_needs_wa_16023588340(struct intel_display *display);
  #endif

+enum intel_display_wa {

+       INTEL_DISPLAY_WA_16023588340,
+};
+
+bool __intel_display_wa(struct intel_display *display, enum intel_display_wa 
wa);
+
+#define _intel_display_wa_expand(__wa) INTEL_DISPLAY_WA_##__wa

Can't we just do this inline instead of adding another macro?

Yes sure will use :

#define intel_display_wa(__display, __wa) \
        __intel_display_wa((__display), INTEL_DISPLAY_WA_##__wa)


Thanks & Regards,

Ankit

+#define intel_display_wa(__display, __wa) __intel_display_wa((__display), 
_intel_display_wa_expand(__wa))
  #endif
diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c 
b/drivers/gpu/drm/i915/display/intel_fbc.c
index ec1ef8694c35..f4b7ff549fd4 100644
--- a/drivers/gpu/drm/i915/display/intel_fbc.c
+++ b/drivers/gpu/drm/i915/display/intel_fbc.c
@@ -1464,7 +1464,7 @@ static int intel_fbc_check_plane(struct 
intel_atomic_state *state,
                return 0;
        }

- if (intel_display_needs_wa_16023588340(display)) {

+       if (intel_display_wa(display, 16023588340)) {
                plane_state->no_fbc_reason = "Wa_16023588340";
                return 0;
        }