Acabei de atualizar o Ubuntu 16.04 via apt upgrade e depois de reiniciar o meu laptop Dell XPS 12-9Q33 a tela foi desligada aleatoriamente. Pressionando os botões no teclado e movendo o mouse não trouxe wake a tela, porém depois de ligar o cabo AC a tela volta a funcionar por 12 segundos, então ele fica preto novamente, e desconectando, em seguida, liga-lo novamente por 12 segundos . Deve-se notar que o sistema ainda responde quando a tela está desligada, o vídeo apenas continua tocando, somente a tela é desligada.
Conteúdo de /var/log/syslog :
Aug 4 18:46:51 hostdt repowerd[2524]: DefaultStateMachine: handle_alarm(display_off)
Aug 4 18:46:51 hostdt repowerd[2524]: BacklightBrightnessControl: Transitioning brightness 0.40 => 0.00 in 40.00 steps 2500.00us each
Aug 4 18:46:51 hostdt repowerd[2524]: BacklightBrightnessControl: Transitioning brightness 0.40 => 0.00 done
Aug 4 18:46:51 hostdt repowerd[2524]: UnityDisplayPowerControl: turn_off()
Aug 4 18:46:51 hostdt repowerd[2524]: UnityScreenService: dbus_emit_brightness(0.000000), brightness_value=0
Aug 4 18:46:51 hostdt repowerd[2524]: UnityScreenService: dbus_emit_DisplayPowerStateChange(0,1)
Aug 4 18:46:51 hostdt repowerd[2524]: LibsuspendSuspendControl: allow_suspend(DefaultStateMachine)
Aug 4 18:46:51 hostdt repowerd[2524]: LibsuspendSuspendControl: Preparing for suspend
Aug 4 18:46:54 hostdt repowerd[2524]: UPowerPowerSource: change_device(/org/freedesktop/UPower/devices/battery_BAT1), is_present=1, state=2, percentage=88.00, temperature=0.00
Aug 4 18:46:54 hostdt repowerd[2524]: UPowerPowerSource: change_device(/org/freedesktop/UPower/devices/battery_BAT1), is_present=1, state=1, percentage=88.00, temperature=0.00
Aug 4 18:46:54 hostdt repowerd[2524]: DefaultStateMachine: handle_power_source_change
Aug 4 18:46:54 hostdt repowerd[2524]: LibsuspendSuspendControl: disallow_suspend(DefaultStateMachine)
Aug 4 18:46:54 hostdt repowerd[2524]: LibsuspendSuspendControl: exiting suspend
Aug 4 18:46:54 hostdt repowerd[2524]: UnityDisplayPowerControl: turn_on()
Aug 4 18:46:54 hostdt repowerd[2524]: BacklightBrightnessControl: Transitioning brightness 0.00 => 0.40 in 40.00 steps 2500.00us each
Aug 4 18:46:55 hostdt repowerd[2524]: BacklightBrightnessControl: Transitioning brightness 0.00 => 0.40 done
Aug 4 18:46:55 hostdt repowerd[2524]: UnityScreenService: dbus_emit_brightness(0.400000), brightness_value=102
Aug 4 18:46:55 hostdt repowerd[2524]: UnityScreenService: dbus_emit_DisplayPowerStateChange(1,4)
Aug 4 18:46:55 hostdt repowerd[2524]: UPowerPowerSource: change_device(/org/freedesktop/UPower/devices/battery_BAT1), is_present=1, state=1, percentage=88.00, temperature=0.00
Acabei de descobrir que suspender o sistema uma vez corrige o problema até a reinicialização e, em seguida, ele precisa ser suspenso novamente.