Re: [RESEND, 22/22] drm/i915/vrr: Add function to check if DC Balance Possible

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 11/3/2025 11:00 AM, Mitul Golani wrote:
> Add function to check if DC Balance possibile on
> requested PIPE and also validate along with DISPLAY_VER
> check.
>
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
> Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_vrr.c | 18 +++++++++++++++++-
>   1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
> index d68306cdbf57..50bb3a1f6105 100644
> --- a/drivers/gpu/drm/i915/display/intel_vrr.c
> +++ b/drivers/gpu/drm/i915/display/intel_vrr.c
> @@ -236,6 +236,22 @@ void intel_vrr_compute_cmrr_timings(struct intel_crtc_state *crtc_state)
>   	crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
>   }
>   
> +static
> +int intel_vrr_dc_balance_possible(const struct intel_crtc_state *crtc_state)
> +{
> +	struct intel_display *display = to_intel_display(crtc_state);
> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> +	enum pipe pipe = crtc->pipe;
> +
> +	/*
> +	 * FIXME: Currently Firmware supports DC Balancing on PIPE A
> +	 * and PIPE B. Account those limitation while computing DC
> +	 * Balance parameters.
> +	 */
> +	return (HAS_VRR_DC_BALANCE(display) &&
> +		((pipe == PIPE_A) || (pipe == PIPE_B)));

Earlier there were plans to have this supported on other pipes, but now 
I think this condition is fixed that only PIPE A/B have this feature. So 
this change can be clubbed with the previous patch.


Regards,

Ankit


> +}
> +
>   static
>   void intel_vrr_compute_vrr_timings(struct intel_crtc_state *crtc_state,
>   				   int vmin, int vmax)
> @@ -249,7 +265,7 @@ void intel_vrr_compute_vrr_timings(struct intel_crtc_state *crtc_state,
>   	crtc_state->vrr.enable = true;
>   	crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
>   
> -	if (HAS_VRR_DC_BALANCE(display))
> +	if (intel_vrr_dc_balance_possible(crtc_state))
>   		crtc_state->vrr.dc_balance.enable = true;
>   }
>