drm/i915/dp: Fail state computation for invalid min/max link BPP values

Make sure that state computation fails if the minimum/maximum link BPP
values got invalid as a result of limiting both of these values
separately to the corresponding source/sink capability limits.

Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20251215192357.172201-14-imre.deak@intel.com

Author: ideak

drivers/gpu/drm/i915/display/intel_dp.c

@@ -2646,16 +2646,21 @@ intel_dp_compute_config_link_bpp_limits(struct intel_dp *intel_dp,
 	limits->link.max_bpp_x16 = max_link_bpp_x16;
 
 	drm_dbg_kms(display->drm,
-		    "[ENCODER:%d:%s][CRTC:%d:%s] DP link limits: pixel clock %d kHz DSC %s max lanes %d max rate %d max pipe_bpp %d max link_bpp " FXP_Q4_FMT "\n",
+		    "[ENCODER:%d:%s][CRTC:%d:%s] DP link limits: pixel clock %d kHz DSC %s max lanes %d max rate %d max pipe_bpp %d min link_bpp " FXP_Q4_FMT " max link_bpp " FXP_Q4_FMT "\n",
 		    encoder->base.base.id, encoder->base.name,
 		    crtc->base.base.id, crtc->base.name,
 		    adjusted_mode->crtc_clock,
 		    str_on_off(dsc),
 		    limits->max_lane_count,
 		    limits->max_rate,
 		    limits->pipe.max_bpp,
+		    FXP_Q4_ARGS(limits->link.min_bpp_x16),
 		    FXP_Q4_ARGS(limits->link.max_bpp_x16));
 
+	if (limits->link.min_bpp_x16 <= 0 ||
+	    limits->link.min_bpp_x16 > limits->link.max_bpp_x16)
+		return false;
+
 	return true;
 }