From: Michel Dänzer <michel.daen...@amd.com>

Turning off the sink in this case causes various issues, because
userspace expects it to stay on until it turns it off explicitly.

Instead, turn the sink off and back on when a display is connected
again. This dance seems necessary for link training to work correctly.

Bugzilla: https://bugs.freedesktop.org/105308
Cc: sta...@vger.kernel.org
Signed-off-by: Michel Dänzer <michel.daen...@amd.com>
---
 drivers/gpu/drm/radeon/radeon_connectors.c | 31 ++++++++++++------------------
 1 file changed, 12 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c 
b/drivers/gpu/drm/radeon/radeon_connectors.c
index 5012f5e47a1e..b108eaabb6df 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -90,25 +90,18 @@ void radeon_connector_hotplug(struct drm_connector 
*connector)
                /* don't do anything if sink is not display port, i.e.,
                 * passive dp->(dvi|hdmi) adaptor
                 */
-               if (dig_connector->dp_sink_type == 
CONNECTOR_OBJECT_ID_DISPLAYPORT) {
-                       int saved_dpms = connector->dpms;
-                       /* Only turn off the display if it's physically 
disconnected */
-                       if (!radeon_hpd_sense(rdev, radeon_connector->hpd.hpd)) 
{
-                               drm_helper_connector_dpms(connector, 
DRM_MODE_DPMS_OFF);
-                       } else if 
(radeon_dp_needs_link_train(radeon_connector)) {
-                               /* Don't try to start link training before we
-                                * have the dpcd */
-                               if (!radeon_dp_getdpcd(radeon_connector))
-                                       return;
-
-                               /* set it to OFF so that 
drm_helper_connector_dpms()
-                                * won't return immediately since the current 
state
-                                * is ON at this point.
-                                */
-                               connector->dpms = DRM_MODE_DPMS_OFF;
-                               drm_helper_connector_dpms(connector, 
DRM_MODE_DPMS_ON);
-                       }
-                       connector->dpms = saved_dpms;
+               if (dig_connector->dp_sink_type == 
CONNECTOR_OBJECT_ID_DISPLAYPORT &&
+                   radeon_hpd_sense(rdev, radeon_connector->hpd.hpd) &&
+                   radeon_dp_needs_link_train(radeon_connector)) {
+                       /* Don't start link training before we have the DPCD */
+                       if (!radeon_dp_getdpcd(radeon_connector))
+                               return;
+
+                       /* Turn the connector off and back on immediately, which
+                        * will trigger link training
+                        */
+                       drm_helper_connector_dpms(connector, DRM_MODE_DPMS_OFF);
+                       drm_helper_connector_dpms(connector, DRM_MODE_DPMS_ON);
                }
        }
 }
-- 
2.16.2

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

Reply via email to