1 files changed, 51 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 1aac59e83bf..5dde80f9e65 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -717,6 +717,51 @@ intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
 	}
 }
 
+static void ironlake_edp_panel_on (struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	unsigned long timeout = jiffies + msecs_to_jiffies(5000);
+	u32 pp, pp_status;
+
+	pp_status = I915_READ(PCH_PP_STATUS);
+	if (pp_status & PP_ON)
+		return;
+
+	pp = I915_READ(PCH_PP_CONTROL);
+	pp |= PANEL_UNLOCK_REGS | POWER_TARGET_ON;
+	I915_WRITE(PCH_PP_CONTROL, pp);
+	do {
+		pp_status = I915_READ(PCH_PP_STATUS);
+	} while (((pp_status & PP_ON) == 0) && !time_after(jiffies, timeout));
+
+	if (time_after(jiffies, timeout))
+		DRM_DEBUG_KMS("panel on wait timed out: 0x%08x\n", pp_status);
+
+	pp &= ~(PANEL_UNLOCK_REGS | EDP_FORCE_VDD);
+	I915_WRITE(PCH_PP_CONTROL, pp);
+}
+
+static void ironlake_edp_panel_off (struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	unsigned long timeout = jiffies + msecs_to_jiffies(5000);
+	u32 pp, pp_status;
+
+	pp = I915_READ(PCH_PP_CONTROL);
+	pp &= ~POWER_TARGET_ON;
+	I915_WRITE(PCH_PP_CONTROL, pp);
+	do {
+		pp_status = I915_READ(PCH_PP_STATUS);
+	} while ((pp_status & PP_ON) && !time_after(jiffies, timeout));
+
+	if (time_after(jiffies, timeout))
+		DRM_DEBUG_KMS("panel off wait timed out\n");
+
+	/* Make sure VDD is enabled so DP AUX will work */
+	pp |= EDP_FORCE_VDD;
+	I915_WRITE(PCH_PP_CONTROL, pp);
+}
+
 static void ironlake_edp_backlight_on (struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -751,14 +796,18 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode)
 	if (mode != DRM_MODE_DPMS_ON) {
 		if (dp_reg & DP_PORT_EN) {
 			intel_dp_link_down(intel_encoder, dp_priv->DP);
-			if (IS_eDP(intel_encoder))
+			if (IS_eDP(intel_encoder)) {
 				ironlake_edp_backlight_off(dev);
+				ironlake_edp_panel_off(dev);
+			}
 		}
 	} else {
 		if (!(dp_reg & DP_PORT_EN)) {
 			intel_dp_link_train(intel_encoder, dp_priv->DP, dp_priv->link_configuration);
-			if (IS_eDP(intel_encoder))
+			if (IS_eDP(intel_encoder)) {
+				ironlake_edp_panel_on(dev);
 				ironlake_edp_backlight_on(dev);
+			}
 		}
 	}
 	dp_priv->dpms_mode = mode;