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

[Nautiyal, Ankit K]

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.gol...@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nauti...@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;
  }