Re: [PATCH v3 5/8] drm/i915/display: move GLK clock gating init to display

Jani Nikula
2026-04-20T12:18:51Z

On Mon, 20 Apr 2026, Luca Coelho <luciano.coelho@intel.com> wrote:
> Move the GLK-specific display clock gating programming into display
> intel_display_clock_gating.c, to remove more dependencies from i915 to
> display registers.
>
> Now that all remaining Gen9-family callers moved into display, we can
> move the shared Gen9 display clock gating helper into display and
> remove the old local helper from intel_clock_gating.c.
>
> Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
> ---
> .../i915/display/intel_display_clock_gating.c | 57 +++++++++++++++++++
> .../i915/display/intel_display_clock_gating.h | 1 +
> drivers/gpu/drm/i915/intel_clock_gating.c | 44 +-------------
> 3 files changed, 59 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_clock_gating.c b/drivers/gpu/drm/i915/display/intel_display_clock_gating.c
> index 59041c807d6d..b2cb18478577 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_clock_gating.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_clock_gating.c
> @@ -6,11 +6,39 @@
> #include <drm/intel/intel_gmd_misc_regs.h>
>
> #include "intel_de.h"
> +#include "intel_display.h"
> #include "intel_display_clock_gating.h"
> +#include "intel_display_core.h"
> #include "intel_display_regs.h"
>
> +static void intel_display_gen9_init_clock_gating(struct intel_display *display)
> +{
> + /* See Bspec note for PSR2_CTL bit 31, Wa#828:skl,bxt,kbl,cfl */
> + intel_de_rmw(display, CHICKEN_PAR1_1, 0, SKL_EDP_PSR_FIX_RDWRAP);
> +
> + /* WaEnableChickenDCPR:skl,bxt,kbl,glk,cfl */
> + intel_de_rmw(display, GEN8_CHICKEN_DCPR_1, 0, MASK_WAKEMEM);
> +
> + /*
> + * WaFbcWakeMemOn:skl,bxt,kbl,glk,cfl
> + * Display WA #0859: skl,bxt,kbl,glk,cfl
> + */
> + intel_de_rmw(display, DISP_ARB_CTL, 0, DISP_FBC_MEMORY_WAKE);
> +}
> +
> void intel_display_skl_init_clock_gating(struct intel_display *display)
> {
> + /*
> + * WaCompressedResourceDisplayNewHashMode:skl,kbl
> + * Display WA #0390: skl,kbl
> + *
> + * Must match Sampler, Pixel Back End, and Media. See
> + * WaCompressedResourceSamplerPbeMediaNewHashMode.
> + */
> + intel_de_rmw(display, CHICKEN_PAR1_1, 0, SKL_DE_COMPRESSED_HASH_MODE);
> +
> + intel_display_gen9_init_clock_gating(display);
> +
> /*
> * WaFbcTurnOffFbcWatermark:skl
> * Display WA #0562: skl
> @@ -20,6 +48,17 @@ void intel_display_skl_init_clock_gating(struct intel_display *display)
>
> void intel_display_kbl_init_clock_gating(struct intel_display *display)
> {
> + /*
> + * WaCompressedResourceDisplayNewHashMode:skl,kbl
> + * Display WA #0390: skl,kbl
> + *
> + * Must match Sampler, Pixel Back End, and Media. See
> + * WaCompressedResourceSamplerPbeMediaNewHashMode.
> + */
> + intel_de_rmw(display, CHICKEN_PAR1_1, 0, SKL_DE_COMPRESSED_HASH_MODE);
> +
> + intel_display_gen9_init_clock_gating(display);
> +
> /*
> * WaFbcTurnOffFbcWatermark:kbl
> * Display WA #0562: kbl
> @@ -29,6 +68,8 @@ void intel_display_kbl_init_clock_gating(struct intel_display *display)
>
> void intel_display_cfl_init_clock_gating(struct intel_display *display)
> {
> + intel_display_gen9_init_clock_gating(display);
> +
> /*
> * WaFbcTurnOffFbcWatermark:cfl
> * Display WA #0562: cfl
> @@ -38,6 +79,8 @@ void intel_display_cfl_init_clock_gating(struct intel_display *display)
>
> void intel_display_bxt_init_clock_gating(struct intel_display *display)
> {
> + intel_display_gen9_init_clock_gating(display);
> +
> /*
> * Wa: Backlight PWM may stop in the asserted state, causing backlight
> * to stay fully on.
> @@ -60,3 +103,17 @@ void intel_display_bxt_init_clock_gating(struct intel_display *display)
> */
> intel_de_rmw(display, DISP_ARB_CTL, 0, DISP_FBC_WM_DIS);
> }
> +
> +void intel_display_glk_init_clock_gating(struct intel_display *display)
> +{
> + intel_display_gen9_init_clock_gating(display);
> +
> + /*
> + * WaDisablePWMClockGating:glk
> + * Backlight PWM may stop in the asserted state, causing backlight
> + * to stay fully on.
> + */
> + intel_de_write(display, GEN9_CLKGATE_DIS_0,
> + intel_de_read(display, GEN9_CLKGATE_DIS_0) |
> + PWM1_GATING_DIS | PWM2_GATING_DIS);
> +}
> diff --git a/drivers/gpu/drm/i915/display/intel_display_clock_gating.h b/drivers/gpu/drm/i915/display/intel_display_clock_gating.h
> index 6bc84a9a4342..a7784db9d97a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_clock_gating.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_clock_gating.h
> @@ -12,5 +12,6 @@ void intel_display_skl_init_clock_gating(struct intel_display *display);
> void intel_display_kbl_init_clock_gating(struct intel_display *display);
> void intel_display_cfl_init_clock_gating(struct intel_display *display);
> void intel_display_bxt_init_clock_gating(struct intel_display *display);
> +void intel_display_glk_init_clock_gating(struct intel_display *display);
>
> #endif /* __INTEL_DISPLAY_CLOCK_GATING_H__ */
> diff --git a/drivers/gpu/drm/i915/intel_clock_gating.c b/drivers/gpu/drm/i915/intel_clock_gating.c
> index 4c1937d922b2..777314e0c75d 100644
> --- a/drivers/gpu/drm/i915/intel_clock_gating.c
> +++ b/drivers/gpu/drm/i915/intel_clock_gating.c
> @@ -49,36 +49,8 @@ struct drm_i915_clock_gating_funcs {
> void (*init_clock_gating)(struct drm_i915_private *i915);
> };
>
> -static void gen9_init_clock_gating(struct drm_i915_private *i915)
> -{
> - if (HAS_LLC(i915)) {

The commit message should explain why removing this is okay.

BR,
Jani.

> - /*
> - * WaCompressedResourceDisplayNewHashMode:skl,kbl
> - * Display WA #0390: skl,kbl
> - *
> - * Must match Sampler, Pixel Back End, and Media. See
> - * WaCompressedResourceSamplerPbeMediaNewHashMode.
> - */
> - intel_uncore_rmw(&i915->uncore, CHICKEN_PAR1_1, 0, SKL_DE_COMPRESSED_HASH_MODE);
> - }
> -
> - /* See Bspec note for PSR2_CTL bit 31, Wa#828:skl,bxt,kbl,cfl */
> - intel_uncore_rmw(&i915->uncore, CHICKEN_PAR1_1, 0, SKL_EDP_PSR_FIX_RDWRAP);
> -
> - /* WaEnableChickenDCPR:skl,bxt,kbl,glk,cfl */
> - intel_uncore_rmw(&i915->uncore, GEN8_CHICKEN_DCPR_1, 0, MASK_WAKEMEM);
> -
> - /*
> - * WaFbcWakeMemOn:skl,bxt,kbl,glk,cfl
> - * Display WA #0859: skl,bxt,kbl,glk,cfl
> - */
> - intel_uncore_rmw(&i915->uncore, DISP_ARB_CTL, 0, DISP_FBC_MEMORY_WAKE);
> -}
> -
> static void bxt_init_clock_gating(struct drm_i915_private *i915)
> {
> - gen9_init_clock_gating(i915);
> -
> /* WaDisableSDEUnitClockGating:bxt */
> intel_uncore_rmw(&i915->uncore, GEN8_UCGCTL6, 0, GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
>
> @@ -93,16 +65,7 @@ static void bxt_init_clock_gating(struct drm_i915_private *i915)
>
> static void glk_init_clock_gating(struct drm_i915_private *i915)
> {
> - gen9_init_clock_gating(i915);
> -
> - /*
> - * WaDisablePWMClockGating:glk
> - * Backlight PWM may stop in the asserted state, causing backlight
> - * to stay fully on.
> - */
> - intel_uncore_write(&i915->uncore, GEN9_CLKGATE_DIS_0,
> - intel_uncore_read(&i915->uncore, GEN9_CLKGATE_DIS_0) |
> - PWM1_GATING_DIS | PWM2_GATING_DIS);
> + intel_display_glk_init_clock_gating(i915->display);
> }
>
> static void g4x_disable_trickle_feed(struct drm_i915_private *dev_priv)
> @@ -282,7 +245,6 @@ static void dg2_init_clock_gating(struct drm_i915_private *i915)
> static void cfl_init_clock_gating(struct drm_i915_private *i915)
> {
> intel_pch_init_clock_gating(i915->display);
> - gen9_init_clock_gating(i915);
>
> /* WAC6entrylatency:cfl */
> intel_uncore_rmw(&i915->uncore, FBC_LLC_READ_CTRL, 0, FBC_LLC_FULLY_OPEN);
> @@ -292,8 +254,6 @@ static void cfl_init_clock_gating(struct drm_i915_private *i915)
>
> static void kbl_init_clock_gating(struct drm_i915_private *i915)
> {
> - gen9_init_clock_gating(i915);
> -
> /* WAC6entrylatency:kbl */
> intel_uncore_rmw(&i915->uncore, FBC_LLC_READ_CTRL, 0, FBC_LLC_FULLY_OPEN);
>
> @@ -312,8 +272,6 @@ static void kbl_init_clock_gating(struct drm_i915_private *i915)
>
> static void skl_init_clock_gating(struct drm_i915_private *i915)
> {
> - gen9_init_clock_gating(i915);
> -
> /* WaDisableDopClockGating:skl */
> intel_uncore_rmw(&i915->uncore, GEN7_MISCCPCTL,
> GEN7_DOP_CLOCK_GATE_ENABLE, 0);

--
Jani Nikula, Intel