drm/i915/gen9: Write dc state debugmask bits only once

DMC debugmask bits should stick so no need to write them
everytime dc state is changed.

v2: Write after firmware has been successfully loaded (Ville)

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455808874-22089-5-git-send-email-mika.kuoppala@intel.com
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 089701b..2b1e85d 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -529,9 +529,6 @@
 	else if (i915.enable_dc == 1 && state > DC_STATE_EN_UPTO_DC5)
 		state = DC_STATE_EN_UPTO_DC5;
 
-	if (state & DC_STATE_EN_UPTO_DC5_DC6_MASK)
-		gen9_set_dc_state_debugmask(dev_priv);
-
 	val = I915_READ(DC_STATE_EN);
 	DRM_DEBUG_KMS("Setting DC state from %02x to %02x\n",
 		      val & mask, state);
@@ -2122,8 +2119,8 @@
 
 	skl_init_cdclk(dev_priv);
 
-	if (dev_priv->csr.dmc_payload)
-		intel_csr_load_program(dev_priv);
+	if (dev_priv->csr.dmc_payload && intel_csr_load_program(dev_priv))
+		gen9_set_dc_state_debugmask(dev_priv);
 }
 
 static void skl_display_core_uninit(struct drm_i915_private *dev_priv)