drm: Make the connector dpms callback return a value, v2.

This is required to properly handle failing dpms calls.
When making a wait in i915 interruptible, I've noticed
that the dpms sequence could fail with -ERESTARTSYS because
it was waiting interruptibly for flips. So from now on
allow drivers to fail in their connector dpms callback.

Encoder and crtc dpms callbacks are unaffected.

Changes since v1:
- Update kerneldoc for the drm helper functions.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Resolve conflicts due to different merge order.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 40c73da..13a6608 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6429,14 +6429,14 @@ struct intel_connector *intel_connector_alloc(void)
 
 /* Even simpler default implementation, if there's really no special case to
  * consider. */
-void intel_connector_dpms(struct drm_connector *connector, int mode)
+int intel_connector_dpms(struct drm_connector *connector, int mode)
 {
 	/* All the simple cases only support two dpms states. */
 	if (mode != DRM_MODE_DPMS_ON)
 		mode = DRM_MODE_DPMS_OFF;
 
 	if (mode == connector->dpms)
-		return;
+		return 0;
 
 	connector->dpms = mode;
 
@@ -6445,6 +6445,8 @@ void intel_connector_dpms(struct drm_connector *connector, int mode)
 		intel_encoder_dpms(to_intel_encoder(connector->encoder), mode);
 
 	intel_modeset_check_state(connector->dev);
+
+	return 0;
 }
 
 /* Simple connector->get_hw_state implementation for encoders that support only