drm/radeon/kms: don't try to be smart in the hpd handler

Attempting to try and turn off disconnected display hw in the
hotput handler lead to more problems than it helped.  For
now just register an event and only attempt the do something
interesting with DP.  Other connectors are just too problematic:
- Some systems have an HPD pin assigned to LVDS, but it's rarely
if ever connected properly and we don't really care about hpd
events on LVDS anyway since it's always connected.
- The HPD pin is wired up correctly for eDP, but we don't really
have to do anything since the events since it's always connected.
- Some HPD pins fire more than once when you connect/disconnect
- etc.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=39882

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 6 insertions, 8 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index 441e0705485..7f65940f918 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -64,18 +64,16 @@ void radeon_connector_hotplug(struct drm_connector *connector)
 	if (connector->dpms != DRM_MODE_DPMS_ON)
 		return;
 
-	/* powering up/down the eDP panel generates hpd events which
-	 * can interfere with modesetting.
-	 */
-	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP)
-		return;
+	/* just deal with DP (not eDP) here. */
+	if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
+		int saved_dpms = connector->dpms;
 
-	/* pre-r600 did not always have the hpd pins mapped accurately to connectors */
-	if (rdev->family >= CHIP_R600) {
-		if (radeon_hpd_sense(rdev, radeon_connector->hpd.hpd))
+		if (radeon_hpd_sense(rdev, radeon_connector->hpd.hpd) &&
+		    radeon_dp_needs_link_train(radeon_connector))
 			drm_helper_connector_dpms(connector, DRM_MODE_DPMS_ON);
 		else
 			drm_helper_connector_dpms(connector, DRM_MODE_DPMS_OFF);
+		connector->dpms = saved_dpms;
 	}
 }