FreeBSD Nvidia drivers Screen Brightness & Power Management

Question

I am running FreeBSD 11RC2 with The current Nvidia-driver version 367.44 and using the nvidia-modeset kernel module that's loaded at startup in my

/etc/rc.conf

file by adding

kld_list="nvidia-modeset"

Here's the info on my GPU

vgapci0@pci0:1:0:0: class=0x030000 card=0x0130106b chip=0x0fe910de rev=0xa1 hdr=0x00
    vendor     = 'NVIDIA Corporation'
    device     = 'GK107M [GeForce GT 750M Mac Edition]'
    class      = display
    subclass   = VGA
    cap 01[60] = powerspec 3  supports D0 D3  current D0
    cap 05[68] = MSI supports 1 message, 64 bit enabled with 1 message
    cap 10[78] = PCI-Express 2 endpoint max data 256(256) RO NS
                 link x8(x16) speed 8.0(8.0) ASPM L0s/L1(L0s/L1)
    cap 09[b4] = vendor (length 20)
    ecap 0002[100] = VC 1 max VC0
    ecap 0004[128] = Power Budgeting 1
    ecap 0001[420] = AER 2 0 fatal 0 non-fatal 0 corrected
    ecap 000b[600] = Vendor 1 ID 1
    ecap 0019[900] = PCIe Sec 1 lane errors 0

Here is the acpi information for this machine : http://paste2.org/LUcIwtzn

device  acpi
debug.acpi.resume_beep: 0
debug.acpi.batt.batt_sleep_ms: 0
debug.acpi.ec.timeout: 750
debug.acpi.ec.polled: 0
debug.acpi.ec.burst: 0
debug.acpi.cpu_unordered: 0
debug.acpi.suspend_bounce: 0
debug.acpi.reset_clock: 1
debug.acpi.default_register_width: 1
debug.acpi.interpreter_slack: 1
debug.acpi.enable_debug_objects: 0
debug.acpi.acpi_ca_version: 20160527
debug.acpi.max_threads: 3
debug.acpi.tasks_hiwater: 40
debug.acpi.max_tasks: 1024
hw.acpi.acline: 1
hw.acpi.battery.info_expire: 5
hw.acpi.battery.units: 1
hw.acpi.battery.state: 0
hw.acpi.battery.time: -1
hw.acpi.battery.life: 97
hw.acpi.cpu.cx_lowest: C2
hw.acpi.reset_video: 0
hw.acpi.handle_reboot: 1
hw.acpi.disable_on_reboot: 0
hw.acpi.verbose: 0
hw.acpi.s4bios: 0
hw.acpi.sleep_delay: 1
hw.acpi.suspend_state: S3
hw.acpi.standby_state: NONE
hw.acpi.lid_switch_state: NONE
hw.acpi.sleep_button_state: S3
hw.acpi.power_button_state: S5
hw.acpi.supported_sleep_state: S3 S4 S5
machdep.idle: acpi
machdep.idle_available: spin, mwait, hlt, acpi
machdep.acpi_root: 2061033492
machdep.acpi_timer_freq: 3579545
dev.acpi_perf.7.%parent: cpu7
dev.acpi_perf.7.%pnpinfo: 
dev.acpi_perf.7.%location: 
dev.acpi_perf.7.%driver: acpi_perf
dev.acpi_perf.7.%desc: 
dev.acpi_perf.6.%parent: cpu6
dev.acpi_perf.6.%pnpinfo: 
dev.acpi_perf.6.%location: 
dev.acpi_perf.6.%driver: acpi_perf
dev.acpi_perf.6.%desc: 
dev.acpi_perf.5.%parent: cpu5
dev.acpi_perf.5.%pnpinfo: 
dev.acpi_perf.5.%location: 
dev.acpi_perf.5.%driver: acpi_perf
dev.acpi_perf.5.%desc: 
dev.acpi_perf.4.%parent: cpu4
dev.acpi_perf.4.%pnpinfo: 
dev.acpi_perf.4.%location: 
dev.acpi_perf.4.%driver: acpi_perf
dev.acpi_perf.4.%desc: 
dev.acpi_perf.3.%parent: cpu3
dev.acpi_perf.3.%pnpinfo: 
dev.acpi_perf.3.%location: 
dev.acpi_perf.3.%driver: acpi_perf
dev.acpi_perf.3.%desc: 
dev.acpi_perf.2.%parent: cpu2
dev.acpi_perf.2.%pnpinfo: 
dev.acpi_perf.2.%location: 
dev.acpi_perf.2.%driver: acpi_perf
dev.acpi_perf.2.%desc: 
dev.acpi_perf.1.%parent: cpu1
dev.acpi_perf.1.%pnpinfo: 
dev.acpi_perf.1.%location: 
dev.acpi_perf.1.%driver: acpi_perf
dev.acpi_perf.1.%desc: 
dev.acpi_perf.0.%parent: cpu0
dev.acpi_perf.0.%pnpinfo: 
dev.acpi_perf.0.%location: 
dev.acpi_perf.0.%driver: acpi_perf
dev.acpi_perf.0.%desc: 
dev.acpi_perf.%parent: 
dev.fpupnp.0.%parent: acpi0
dev.atdma.0.%parent: acpi0
dev.acpi_button.1.%parent: acpi0
dev.acpi_button.1.%pnpinfo: _HID=PNP0C0E _UID=0
dev.acpi_button.1.%location: handle=\_SB_.SLPB
dev.acpi_button.1.%driver: acpi_button
dev.acpi_button.1.%desc: Sleep Button
dev.acpi_button.0.%parent: acpi0
dev.acpi_button.0.%pnpinfo: _HID=PNP0C0C _UID=0
dev.acpi_button.0.%location: handle=\_SB_.PWRB
dev.acpi_button.0.%driver: acpi_button
dev.acpi_button.0.%desc: Power Button
dev.acpi_button.%parent: 
dev.acpi_lid.0.wake: 1
dev.acpi_lid.0.%parent: acpi0
dev.acpi_lid.0.%pnpinfo: _HID=PNP0C0D _UID=0
dev.acpi_lid.0.%location: handle=\_SB_.LID0
dev.acpi_lid.0.%driver: acpi_lid
dev.acpi_lid.0.%desc: Control Method Lid Switch
dev.acpi_lid.%parent: 
dev.acpi_acad.0.wake: 0
dev.acpi_acad.0.%parent: acpi0
dev.acpi_acad.0.%pnpinfo: _HID=ACPI0003 _UID=0
dev.acpi_acad.0.%location: handle=\_SB_.ADP1
dev.acpi_acad.0.%driver: acpi_acad
dev.acpi_acad.0.%desc: AC Adapter
dev.acpi_acad.%parent: 
dev.battery.0.%parent: acpi0
dev.pcib.0.%parent: acpi0
dev.pci_link.7.%parent: acpi0
dev.pci_link.6.%parent: acpi0
dev.pci_link.5.%parent: acpi0
dev.pci_link.4.%parent: acpi0
dev.pci_link.3.%parent: acpi0
dev.pci_link.2.%parent: acpi0
dev.pci_link.1.%parent: acpi0
dev.pci_link.0.%parent: acpi0
dev.acpi_timer.0.%parent: acpi0
dev.acpi_timer.0.%pnpinfo: unknown
dev.acpi_timer.0.%location: unknown
dev.acpi_timer.0.%driver: acpi_timer
dev.acpi_timer.0.%desc: 24-bit timer at 3.579545MHz
dev.acpi_timer.%parent: 
dev.attimer.0.%parent: acpi0
dev.atrtc.0.%parent: acpi0
dev.cpu.7.%parent: acpi0
dev.cpu.6.%parent: acpi0
dev.cpu.5.%parent: acpi0
dev.cpu.4.%parent: acpi0
dev.cpu.3.%parent: acpi0
dev.cpu.2.%parent: acpi0
dev.cpu.1.%parent: acpi0
dev.cpu.0.%parent: acpi0
dev.acpi_sysresource.2.%parent: acpi0
dev.acpi_sysresource.2.%pnpinfo: _HID=PNP0C01 _UID=2
dev.acpi_sysresource.2.%location: handle=\_SB_.MEM2
dev.acpi_sysresource.2.%driver: acpi_sysresource
dev.acpi_sysresource.2.%desc: System Resource
dev.acpi_sysresource.1.%parent: acpi0
dev.acpi_sysresource.1.%pnpinfo: _HID=PNP0C02 _UID=1
dev.acpi_sysresource.1.%location: handle=\_SB_.PCI0.PDRC
dev.acpi_sysresource.1.%driver: acpi_sysresource
dev.acpi_sysresource.1.%desc: System Resource
dev.acpi_sysresource.0.%parent: acpi0
dev.acpi_sysresource.0.%pnpinfo: _HID=PNP0C02 _UID=2
dev.acpi_sysresource.0.%location: handle=\_SB_.PCI0.LPCB.LDRC
dev.acpi_sysresource.0.%driver: acpi_sysresource
dev.acpi_sysresource.0.%desc: System Resource
dev.acpi_sysresource.%parent: 
dev.hpet.0.%parent: acpi0
dev.acpi_ec.0.wake: 0
dev.acpi_ec.0.%parent: acpi0
dev.acpi_ec.0.%pnpinfo: _HID=PNP0C09 _UID=0
dev.acpi_ec.0.%location: handle=\_SB_.PCI0.LPCB.EC__
dev.acpi_ec.0.%driver: acpi_ec
dev.acpi_ec.0.%desc: Embedded Controller: GPE 0x17, ECDT
dev.acpi_ec.%parent: 
dev.acpi.0.%parent: nexus0
dev.acpi.0.%pnpinfo: 
dev.acpi.0.%location: 
dev.acpi.0.%driver: acpi
dev.acpi.0.%desc: APPLE Apple00
dev.acpi.%parent:

I came from running linux and typically there's a video or some acpi settings that will control the brightness of the screen but on FreeBSD, there doesn't seem to be anything like this so my monitor is constantly at 100% brightness. Shouldn't there be some way to dim the brightness through the acpi interface?

Can I get some support to be able to dim the screen brightness?

[edit] Here is the output of my xorg.conf

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 367.35  Wed Sep  7 17:03:49 CST 2016

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "Files"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/sysmouse"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "keyboard"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       28.0 - 33.0
    VertRefresh     43.0 - 72.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Answer 1

I struggled with brightness on Dell L702X with Nvidia GT550M. You can see what I've found in this thread (link). Maybe some of those things will work for you.

I wasn't able to use xbacklight(1) (or activate the brightness control keys) but I've found a couple of other ways to change the brightness:

• xrandr(1)

  Thanks to this post (link) I was able to change the brightness of the external monitor using xrandr. The command looks like this:

  xrandr --output HDMI-0 --brightness 0.9
  

  The default value seems to be 1.

• redshift(1)

  Redshift is a software allowing you to change the temperature of your screen. It has -b, -t and -g options which might come handy (see man redshift for more details).

---

See also

• https://wiki.freebsd.org/Graphics/Brightness
• https://wiki.freebsd.org/Graphics/FAQ