drm/i915/chv: Turn off dclkp after the PLL has been disabled

During the enable sequence we first enable the dclkp output to the
display controller, and then enable the PLL. Do the opposite during
the disable sequence.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -1694,6 +1694,7 @@ static void vlv_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
 
 static void chv_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
 {
+	enum dpio_channel port = vlv_pipe_to_channel(pipe);
 	u32 val;
 
 	/* Make sure the pipe isn't still relying on us */
@@ -1705,6 +1706,15 @@ static void chv_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
 		val |= DPLL_INTEGRATED_CRI_CLK_VLV;
 	I915_WRITE(DPLL(pipe), val);
 	POSTING_READ(DPLL(pipe));
+
+	mutex_lock(&dev_priv->dpio_lock);
+
+	/* Disable 10bit clock to display controller */
+	val = vlv_dpio_read(dev_priv, pipe, CHV_CMN_DW14(port));
+	val &= ~DPIO_DCLKP_EN;
+	vlv_dpio_write(dev_priv, pipe, CHV_CMN_DW14(port), val);
+
+	mutex_unlock(&dev_priv->dpio_lock);
 }
 
 void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
@@ -5538,11 +5548,6 @@ static void chv_update_pll(struct intel_crtc *crtc)
 	val &= ~(DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET);
 	vlv_dpio_write(dev_priv, pipe, VLV_PCS_DW0(port), val);
 
-	/* Disable 10bit clock to display controller */
-	val = vlv_dpio_read(dev_priv, pipe, CHV_CMN_DW14(port));
-	val &= ~DPIO_DCLKP_EN;
-	vlv_dpio_write(dev_priv, pipe, CHV_CMN_DW14(port), val);
-
 	/* p1 and p2 divider */
 	vlv_dpio_write(dev_priv, pipe, CHV_CMN_DW13(port),
 			5 << DPIO_CHV_S1_DIV_SHIFT |