From 7bf11bc2f716f6824b3b3d418319967213aab2a5 Mon Sep 17 00:00:00 2001 From: Mitul Golani Date: Tue, 23 Dec 2025 16:15:30 +0530 Subject: [PATCH] drm/i915/vrr: Add function to check if DC Balance Possible Add a function that checks if DC Balance enabling is possible on the requested PIPE. Apart from the DISPLAY_VER check, account for current firmware limitations, which only allow DC Balance on PIPE A and PIPE B. v2: Rephrased commit message. (Ankit) Signed-off-by: Mitul Golani Reviewed-by: Ankit Nautiyal Signed-off-by: Ankit Nautiyal Link: https://patch.msgid.link/20251223104542.2688548-9-mitulkumar.ajitkumar.golani@intel.com --- drivers/gpu/drm/i915/display/intel_vrr.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c index 952e3c31bacc..dbfe56e8973d 100644 --- a/drivers/gpu/drm/i915/display/intel_vrr.c +++ b/drivers/gpu/drm/i915/display/intel_vrr.c @@ -351,13 +351,28 @@ int intel_vrr_compute_vmax(struct intel_connector *connector, return vmax; } +static bool 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))); +} + static void intel_vrr_dc_balance_compute_config(struct intel_crtc_state *crtc_state) { int guardband_usec, adjustment_usec; struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode; - if (!HAS_VRR_DC_BALANCE(display) || !crtc_state->vrr.enable) + if (!intel_vrr_dc_balance_possible(crtc_state) || !crtc_state->vrr.enable) return; crtc_state->vrr.dc_balance.vmax = crtc_state->vrr.vmax; @@ -839,7 +854,7 @@ void intel_vrr_get_dc_balance_config(struct intel_crtc_state *crtc_state) struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); enum pipe pipe = crtc->pipe; - if (!HAS_VRR_DC_BALANCE(display)) + if (!intel_vrr_dc_balance_possible(crtc_state)) return; reg_val = intel_de_read(display, PIPEDMC_DCB_VMIN(pipe)); -- 2.47.3