drm/i915/display/icl+: Check if DMC is fused off

Check if DMC is fused off and handle it.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Martin Peres <martin.peres@linux.intel.com>
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191026001323.216052-4-jose.souza@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -7750,6 +7750,7 @@ enum {
 #define   SKL_DFSM_CDCLK_LIMIT_540	(1 << 23)
 #define   SKL_DFSM_CDCLK_LIMIT_450	(2 << 23)
 #define   SKL_DFSM_CDCLK_LIMIT_337_5	(3 << 23)
+#define   ICL_DFSM_DMC_DISABLE		(1 << 23)
 #define   SKL_DFSM_PIPE_A_DISABLE	(1 << 30)
 #define   SKL_DFSM_PIPE_B_DISABLE	(1 << 21)
 #define   SKL_DFSM_PIPE_C_DISABLE	(1 << 28)

drivers/gpu/drm/i915/intel_device_info.c

@@ -987,6 +987,9 @@ void intel_device_info_runtime_init(struct drm_i915_private *dev_priv)
 
 		if (dfsm & SKL_DFSM_DISPLAY_PM_DISABLE)
 			info->display.has_fbc = 0;
+
+		if (INTEL_GEN(dev_priv) >= 11 && (dfsm & ICL_DFSM_DMC_DISABLE))
+			info->display.has_csr = 0;
 	}
 
 	/* Initialize slice/subslice/EU info */