Screen could not recover from screen saving when using modesetting with atomic modeset

Hi guys,

I'm using modesetting on an embedded system, and found that the screen could not come back after exiting screen save mode.

It looks like the drmmode_output_dpms() doesn't handle DPMSModeOn to enable the output:

    if (ms->atomic_modeset) {
        if (mode != DPMSModeOn && !ms->pending_modeset)
            drmmode_output_disable(output);
    } else {
        drmModeConnectorSetProperty(drmmode->fd, koutput->connector_id,
                                    drmmode_output->dpms_enum_id, mode);
    }