mensaje de fallo al iniciar Failed to start Load/Save Screen Backlight Brightness of backlight:

buenos dias

de nuevo solicitando su ayuda tengo una PC con tarjeta madre asus P8 z77-v lx  le instale debian sid al momento de iniciar me manda un mensaje de fallo, no lo cataba bien ya que pasaba muy rapido, utilizando journalctl -f -p err me dio los siguiente mensajes

-- Logs begin at sáb 2016-09-10 08:10:09 CST. --
sep 10 08:10:13 pcgacs systemd-backlight[752]: Failed to get backlight or LED device 'backlight:acpi_video0': No such device
sep 10 08:10:13 pcgacs systemd[1]: Failed to start Load/Save Screen Backlight Brightness of backlight:acpi_video0.
sep 10 08:10:15 pcgacs minissdpd[819]: setsockopt(udp, IP_ADD_MEMBERSHIP)(0.0.0.0): No such device
sep 10 08:11:45 pcgacs kernel: usb 2-1-port8: disabled by hub (EMI?), re-enabling...
sep 10 08:12:11 pcgacs pulseaudio[1197]: [pulseaudio] bluez5-util.c: GetManagedObjects() failed: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

Buscando por la red el mismo falla me encontre que que solicitaban lo siguiente, a mi no me dice mucho pero talves de idea para que me puedan ayudar

journalctl -ab-1 -u dm_name
Specifying boot ID has no effect, no persistent journal was found

systemctl list-units --type=service
  UNIT                        LOAD   ACTIVE SUB     DESCRIPTION
  accounts-daemon.service     loaded active running Accounts Service
  avahi-daemon.service        loaded active running Avahi mDNS/DNS-SD Stack
  colord.service              loaded active running Manage, Install and Generate
  console-setup.service       loaded active exited  Set console font and keymap
  cron.service                loaded active running Regular background program p
  dbus.service                loaded active running D-Bus System Message Bus
  getty@tty1.service          loaded active running Getty on tty1
  irqbalance.service          loaded active running LSB: daemon to balance inter
  keyboard-setup.service      loaded active exited  Set the console keyboard lay
  kmod-static-nodes.service   loaded active exited  Create list of required stat
  lm-sensors.service          loaded active exited  Initialize hardware monitori
  minissdpd.service           loaded active running keep memory of all UPnP devi
  ModemManager.service        loaded active running Modem Manager
  networking.service          loaded active exited  Raise network interfaces
  NetworkManager-wait-online.service loaded active exited  Network Manager Wait 
  NetworkManager.service      loaded active running Network Manager
  polkitd.service             loaded active running Authenticate and Authorize U
  rc-local.service            loaded active exited  /etc/rc.local Compatibility
  rsyslog.service             loaded active running System Logging Service
  rtkit-daemon.service        loaded active running RealtimeKit Scheduling Polic
  slim.service                loaded active running SLiM Simple Login Manager
● systemd-backlight@backlight:acpi_video0.service loaded failed failed  Load/Sav

de momento solo he modificado la linia de inicio del grub y me quedo asi, y en una ocaciones da el error en otras no, si elimino la linea "acpi_osi=!Windows 2012" siempre me da la falla

cat /proc/cmdlineBOOT_IMAGE=/boot/vmlinuz-4.7.0-1-amd64 root=UUID=bdbfae3a-7c4f-40f5-aaa0-d49a73b1e2ce ro quiet splash "acpi_osi=!Windows 2012"

muchas gracias por la ayuda que me brinden