drm/nv50: set DP display power state during DPMS

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nv50_sor.c

@@ -115,8 +115,22 @@ nv50_sor_dpms(struct drm_encoder *encoder, int mode)
 			 nv_rd32(dev, NV50_PDISPLAY_SOR_DPMS_STATE(or)));
 	}
 
-	if (nv_encoder->dcb->type == OUTPUT_DP && mode == DRM_MODE_DPMS_ON)
+	if (nv_encoder->dcb->type == OUTPUT_DP) {
+		struct nouveau_i2c_chan *auxch;
+
+		auxch = nouveau_i2c_find(dev, nv_encoder->dcb->i2c_index);
+		if (!auxch)
+			return;
+
+		if (mode == DRM_MODE_DPMS_ON) {
+			u8 status = DP_SET_POWER_D0;
+			nouveau_dp_auxch(auxch, 8, DP_SET_POWER, &status, 1);
 			nouveau_dp_link_train(encoder);
+		} else {
+			u8 status = DP_SET_POWER_D3;
+			nouveau_dp_auxch(auxch, 8, DP_SET_POWER, &status, 1);
+		}
+	}
 }
 
 static void