[PATCH v2] drm/i915: update eDP MSO pipe mask for newer platforms

[Ville Syrjälä]

On Fri, Jan 26, 2024 at 12:03:09PM +0200, Luca Coelho wrote:
> Starting from display version 14, pipes A and B are supported in eDP
> MSO.  After display version 20 there are no restrictions.
> 
> Update the function that returns the pipe mask for eDP MSO
> accordingly.
> 
> Bspec: 68923, 55473
> Cc: Jani Nikula <jani.nikula at intel.com>
> Cc: James Ausmus <james.ausmus at intel.com>
> Reviewed-by: Gustavo Sousa <gustavo.sousa at intel.com>
> Signed-off-by: Luca Coelho <luciano.coelho at intel.com>
> ---
> 
> In v2:
>    * allow pipes A and B from ver 14 to 20 [Gustavo]
> 
> 
> drivers/gpu/drm/i915/display/intel_ddi.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 922194b957be..29a616a8e72d 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2336,13 +2336,20 @@ static void intel_ddi_power_up_lanes(struct intel_encoder *encoder,
>  	}
>  }
>  
> -/* Splitter enable for eDP MSO is limited to certain pipes. */
> +/*
> + * Splitter enable for eDP MSO is limited to certain pipes on certain
> + * platforms.
> + */
>  static u8 intel_ddi_splitter_pipe_mask(struct drm_i915_private *i915)
>  {
> -	if (IS_ALDERLAKE_P(i915))
> +
> +	if (IS_ALDERLAKE_P(i915) ||
> +	    IS_DISPLAY_IP_RANGE(i915, IP_VER(14, 0), IP_VER(20, 0)))
>  		return BIT(PIPE_A) | BIT(PIPE_B);
> -	else
> +	else if (DISPLAY_VER(i915) < 14)
>  		return BIT(PIPE_A);
> +
> +	return ~0;

That looks rather confusing. I'd make it something like:

if (VER >= whatever_is_the_new_version_that_i_can't_easily_find_from_bspec)
	return ~0;
else if (VER >= 14 || ADL)
	return A | B;
else
	return A;


>  }
>  
>  static void intel_ddi_mso_get_config(struct intel_encoder *encoder,
> -- 
> 2.39.2

-- 
Ville Syrjälä
Intel