drm/radeon/kms: fix shared ddc handling

Connectors with a shared ddc line can be connected to different
encoders.

Reported by Pasi Kärkkäinen <pasik@iki.fi> on dri-devel

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

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index 0c7ccc6961a3..f58f8bd8f77b 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -785,7 +785,9 @@ static enum drm_connector_status radeon_dvi_detect(struct drm_connector *connect
                                         if (connector == list_connector)
                                                 continue;
                                         list_radeon_connector = to_radeon_connector(list_connector);
-                                        if (radeon_connector->devices == list_radeon_connector->devices) {
+                                        if (list_radeon_connector->shared_ddc &&
+                                            (list_radeon_connector->ddc_bus->rec.i2c_id ==
+                                             radeon_connector->ddc_bus->rec.i2c_id)) {
                                                 if (drm_detect_hdmi_monitor(radeon_connector->edid)) {
                                                         if (connector->connector_type == DRM_MODE_CONNECTOR_DVID) {
                                                                 kfree(radeon_connector->edid);