Re: [PATCH 07/12] drm/i915/de: Add intel_de_read16()

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 25 Mar 2026, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> We'll need a replacement for intel_uncore_read16() in order to
> untangle intel_mchbar_read16() from uncore. As with the 8 bit
> counterpart this doesn't need to work on modern platforms
> so we can forgo all the DMC wakelock stuff and whatnot.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_de.c | 8 ++++++++
>  drivers/gpu/drm/i915/display/intel_de.h | 1 +
>  2 files changed, 9 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_de.c b/drivers/gpu/drm/i915/display/intel_de.c
> index d2a418da2d54..a96e83d76eaa 100644
> --- a/drivers/gpu/drm/i915/display/intel_de.c
> +++ b/drivers/gpu/drm/i915/display/intel_de.c
> @@ -176,3 +176,11 @@ void intel_de_write8(struct intel_display *display, i915_reg_t reg, u8 val)
>  
>  	intel_uncore_write8(__to_uncore(display), reg, val);
>  }
> +
> +u16 intel_de_read16(struct intel_display *display, i915_reg_t reg)
> +{
> +	/* this is only used on MCHBAR registers on pre-SNB */
> +	drm_WARN_ON(display->drm, DISPLAY_VER(display) >= 6);
> +
> +	return intel_uncore_read16(__to_uncore(display), reg);
> +}
> diff --git a/drivers/gpu/drm/i915/display/intel_de.h b/drivers/gpu/drm/i915/display/intel_de.h
> index f87b84ab9d6d..3f9861b7a589 100644
> --- a/drivers/gpu/drm/i915/display/intel_de.h
> +++ b/drivers/gpu/drm/i915/display/intel_de.h
> @@ -19,6 +19,7 @@ static inline struct intel_uncore *__to_uncore(struct intel_display *display)
>  
>  u8 intel_de_read8(struct intel_display *display, i915_reg_t reg);
>  void intel_de_write8(struct intel_display *display, i915_reg_t reg, u8 val);
> +u16 intel_de_read16(struct intel_display *display, i915_reg_t reg);
>  
>  static inline u32
>  intel_de_read(struct intel_display *display, i915_reg_t reg)

-- 
Jani Nikula, Intel