drm: Only set DPMS ON when actually configuring a mode

In drm_crtc_helper_set_config, instead of always forcing all outputs
to DRM_MODE_DPMS_ON, only set them if the CRTC is actually getting a
mode set, as any mode set will turn all outputs on.

This fixes https://lkml.org/lkml/2011/1/24/457

Signed-off-by: Keith Packard <keithp@keithp.com>
Cc: stable@kernel.org (2.6.37)
Reported-and-tested-by: Carlos R. Mafra <crmafra2@gmail.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpu/drm/drm_crtc_helper.c

@@ -665,6 +665,12 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
 				ret = -EINVAL;
 				goto fail;
 			}
+			DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
+			for (i = 0; i < set->num_connectors; i++) {
+				DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
+					      drm_get_connector_name(set->connectors[i]));
+				set->connectors[i]->dpms = DRM_MODE_DPMS_ON;
+			}
 		}
 		drm_helper_disable_unused_functions(dev);
 	} else if (fb_changed) {
@@ -681,12 +687,6 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
 			goto fail;
 		}
 	}
-	DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
-	for (i = 0; i < set->num_connectors; i++) {
-		DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
-			      drm_get_connector_name(set->connectors[i]));
-		set->connectors[i]->dpms = DRM_MODE_DPMS_ON;
-	}
 
 	kfree(save_connectors);
 	kfree(save_encoders);