[PATCHv2 10/10] drm/i915/histogram: Enable pipe dithering

[Kandpal, Suraj]

> -----Original Message-----
> From: Intel-xe <intel-xe-bounces at lists.freedesktop.org> On Behalf Of Arun R
> Murthy
> Sent: Monday, December 9, 2024 9:55 PM
> To: intel-xe at lists.freedesktop.org; intel-gfx at lists.freedesktop.org; dri-
> devel at lists.freedesktop.org
> Cc: Murthy, Arun R <arun.r.murthy at intel.com>
> Subject: [PATCHv2 10/10] drm/i915/histogram: Enable pipe dithering
> 
> Enable pipe dithering while enabling histogram to overcome some atrifacts
> seen on the screen.

The commit message here should add color processing in histogram creates color banding and dithering helps avoid that.

Other LGTM,
Reviewed-by: Suraj Kandpal <suraj.kandpal at intel.com>

> 
> Signed-off-by: Arun R Murthy <arun.r.murthy at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_histogram.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_histogram.c
> b/drivers/gpu/drm/i915/display/intel_histogram.c
> index d503d0f0a5ee..545376ae365b 100644
> --- a/drivers/gpu/drm/i915/display/intel_histogram.c
> +++ b/drivers/gpu/drm/i915/display/intel_histogram.c
> @@ -29,6 +29,13 @@ struct intel_histogram {
>  	u32 bin_data[HISTOGRAM_BIN_COUNT];
>  };
> 
> +static void intel_histogram_enable_dithering(struct intel_display *display,
> +					     enum pipe pipe)
> +{
> +	intel_de_rmw(display, PIPE_MISC(pipe), PIPE_MISC_DITHER_ENABLE,
> +		     PIPE_MISC_DITHER_ENABLE);
> +}
> +
>  static void set_bin_index_0(struct intel_display *display, enum pipe pipe)  {
>  	if (DISPLAY_VER(display) >= 20)
> @@ -207,6 +214,9 @@ static int intel_histogram_enable(struct intel_crtc
> *intel_crtc)
>  	if (histogram->enable)
>  		return 0;
> 
> +	/* Pipe Dithering should be enabled with histogram */
> +	intel_histogram_enable_dithering(display, pipe);
> +
>  	 /* enable histogram, clear DPST_BIN reg and select TC function */
>  	if (DISPLAY_VER(display) >= 20)
>  		intel_de_rmw(display, DPST_CTL(pipe),
> --
> 2.25.1