4.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Deucher <alexander.deucher@xxxxxxx> commit a887adadb7b9ef9eb4ee48e4ad575aefcfd1db14 upstream. This is a port of: DRM - radeon: Don't link train DisplayPort on HPD until we get the dpcd to amdgpu. Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c @@ -75,6 +75,11 @@ void amdgpu_connector_hotplug(struct drm if (!amdgpu_display_hpd_sense(adev, amdgpu_connector->hpd.hpd)) { drm_helper_connector_dpms(connector, DRM_MODE_DPMS_OFF); } else if (amdgpu_atombios_dp_needs_link_train(amdgpu_connector)) { + /* Don't try to start link training before we + * have the dpcd */ + if (!amdgpu_atombios_dp_get_dpcd(amdgpu_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. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html