drm/i915: eDP mode set sequence corrections

We should disable the panel first when shutting down an eDP link.  And
when turning one on, the panel needs to be enabled before link training
or eDP I/O won't be enabled.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/gpu/drm/i915/intel_dp.c

@@ -840,22 +840,21 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode)
 	uint32_t dp_reg = I915_READ(intel_dp->output_reg);
 
 	if (mode != DRM_MODE_DPMS_ON) {
-		if (dp_reg & DP_PORT_EN) {
-			intel_dp_link_down(intel_dp);
 		if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp)) {
 			ironlake_edp_backlight_off(dev);
 			ironlake_edp_panel_off(dev);
 		}
-		}
+		if (dp_reg & DP_PORT_EN)
+			intel_dp_link_down(intel_dp);
 	} else {
 		if (!(dp_reg & DP_PORT_EN)) {
-			intel_dp_link_train(intel_dp);
-			if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp)) {
+			if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
 				ironlake_edp_panel_on(dev);
+			intel_dp_link_train(intel_dp);
+			if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
 				ironlake_edp_backlight_on(dev);
 		}
 	}
-	}
 	intel_dp->dpms_mode = mode;
 }