drm/i915: Only wait for required lanes in vlv_wait_port_ready()

Currently vlv_wait_port_ready() waits for all four lanes on the
appropriate channel. This no longer works on CHV when the unused
lanes may be power gated. So pass in a mask of lanes that the
caller is expecting to be ready.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by:  Deepak S<deepak.s@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -1844,7 +1844,8 @@ static void chv_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
 }
 
 void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
-		struct intel_digital_port *dport)
+			 struct intel_digital_port *dport,
+			 unsigned int expected_mask)
 {
 	u32 port_mask;
 	int dpll_reg;
@@ -1857,6 +1858,7 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
 	case PORT_C:
 		port_mask = DPLL_PORTC_READY_MASK;
 		dpll_reg = DPLL(0);
+		expected_mask <<= 4;
 		break;
 	case PORT_D:
 		port_mask = DPLL_PORTD_READY_MASK;
@@ -1866,9 +1868,9 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
 		BUG();
 	}
 
-	if (wait_for((I915_READ(dpll_reg) & port_mask) == 0, 1000))
-		WARN(1, "timed out waiting for port %c ready: 0x%08x\n",
-		     port_name(dport->port), I915_READ(dpll_reg));
+	if (wait_for((I915_READ(dpll_reg) & port_mask) == expected_mask, 1000))
+		WARN(1, "timed out waiting for port %c ready: got 0x%x, expected 0x%x\n",
+		     port_name(dport->port), I915_READ(dpll_reg) & port_mask, expected_mask);
 }
 
 static void intel_prepare_shared_dpll(struct intel_crtc *crtc)

drivers/gpu/drm/i915/intel_dp.c

@@ -2497,6 +2497,7 @@ static void intel_enable_dp(struct intel_encoder *encoder)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
 	uint32_t dp_reg = I915_READ(intel_dp->output_reg);
+	unsigned int lane_mask = 0x0;
 
 	if (WARN_ON(dp_reg & DP_PORT_EN))
 		return;
@@ -2515,7 +2516,8 @@ static void intel_enable_dp(struct intel_encoder *encoder)
 	pps_unlock(intel_dp);
 
 	if (IS_VALLEYVIEW(dev))
-		vlv_wait_port_ready(dev_priv, dp_to_dig_port(intel_dp));
+		vlv_wait_port_ready(dev_priv, dp_to_dig_port(intel_dp),
+				    lane_mask);
 
 	intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
 	intel_dp_start_link_train(intel_dp);

drivers/gpu/drm/i915/intel_drv.h

@@ -1013,7 +1013,8 @@ intel_wait_for_vblank(struct drm_device *dev, int pipe)
 }
 int ironlake_get_lanes_required(int target_clock, int link_bw, int bpp);
 void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
-			 struct intel_digital_port *dport);
+			 struct intel_digital_port *dport,
+			 unsigned int expected_mask);
 bool intel_get_load_detect_pipe(struct drm_connector *connector,
 				struct drm_display_mode *mode,
 				struct intel_load_detect_pipe *old,

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1324,7 +1324,7 @@ static void vlv_hdmi_pre_enable(struct intel_encoder *encoder)
 
 	intel_enable_hdmi(encoder);
 
-	vlv_wait_port_ready(dev_priv, dport);
+	vlv_wait_port_ready(dev_priv, dport, 0x0);
 }
 
 static void vlv_hdmi_pre_pll_enable(struct intel_encoder *encoder)
@@ -1641,7 +1641,7 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder)
 
 	intel_enable_hdmi(encoder);
 
-	vlv_wait_port_ready(dev_priv, dport);
+	vlv_wait_port_ready(dev_priv, dport, 0x0);
 }
 
 static void intel_hdmi_destroy(struct drm_connector *connector)