Linux backlight driver

[guillaumezin]

Hello,

I wrote a little Linux driver based on Andy Wingo's work (http://wingolog.org/pub/nvbacklight-0.1.tar.bz2) and MacTel Team (https://launchpad.net/~mactel-suppor..._filter=karmic) that enables the control of laptop backlight connected to nVidia chip using the /sys/class/backlight interface.

Source and binary download are now available on github: https://github.com/guillaumezin/nvidiabl

Guillaume

[bistory]

That's great man !
I'll test it tomorrow (it's a little bit too late now for me).
You're like Santa you made my day !

[mdoube]

Tried installing the .deb on Ubuntu Karmic, which completed OK.

No improvement in backlight control though:
Sony Vaio VGN SZ650N with nVidia 8400M GS

I use nvclock / smartdimmer and acpi events in /etc/acpi/events to get backlight control from Fn keys.

01:00.0 VGA compatible controller [0300]: nVidia Corporation G86 [GeForce 8400M GS] [10de:0427] (rev a1)
	Subsystem: Sony Corporation Device [104d:9008]
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0
	Interrupt: pin A routed to IRQ 16
	Region 0: Memory at ca000000 (32-bit, non-prefetchable) [size=16M]
	Region 1: Memory at d0000000 (64-bit, prefetchable) [size=256M]
	Region 3: Memory at c8000000 (64-bit, non-prefetchable) [size=32M]
	Region 5: I/O ports at 2000 [size=128]
	Capabilities: [60] Power Management version 2
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [68] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-
		Address: 0000000000000000  Data: 0000
	Capabilities: [78] Express (v1) Endpoint, MSI 00
		DevCap:	MaxPayload 128 bytes, PhantFunc 0, Latency L0s <512ns, L1 <4us
			ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
		DevCtl:	Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
			RlxdOrd+ ExtTag+ PhantFunc- AuxPwr- NoSnoop+
			MaxPayload 128 bytes, MaxReadReq 512 bytes
		DevSta:	CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend-
		LnkCap:	Port #0, Speed 2.5GT/s, Width x16, ASPM L0s L1, Latency L0 <512ns, L1 <4us
			ClockPM- Suprise- LLActRep- BwNot-
		LnkCtl:	ASPM L0s L1 Enabled; RCB 128 bytes Disabled- Retrain- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 2.5GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
	Capabilities: [100] Virtual Channel <?>
	Capabilities: [128] Power Budgeting <?>
	Capabilities: [600] Vendor Specific Information <?>
	Kernel driver in use: nvidia
	Kernel modules: nvidia, nvidiafb

[bistory]

I tested !
I used the .deb, I've a sony vaio VGN-FZ11E with a Nvidia 8400M GT and ...

IT WORKS ! (Tested on Ubuntu Karmic 32 bits).

I've a complete backlight controll from fn keys to dim when idle !

Thanks a lot

[ercoppa]

Why do you not using nvidia_bl module (by MacTel Team)? It works like charm.

[guillaumezin]

Originally Posted by ercoppa

Why do you not using nvidia_bl module (by MacTel Team)? It works like charm.

Well, because I wasn't aware that there was already one, like a lot of people here: https://bugs.launchpad.net/ubuntu/+s...il/+bug/345531

Originally Posted by mdoube

I tried it, its autodetection works but I can't reach 100%. I will see if I can see why.

Tried installing the .deb on Ubuntu Karmic, which completed OK.

No improvement in backlight control though:
Sony Vaio VGN SZ650N with nVidia 8400M GS

Did you tried different "model" option for the module?

Guillaume

[Dragoran]

nVidia staff is of course free to ship this driver with theirs, and to give me some hints on how to autodetect backlight and chipset!

The correct way here is to send your driver upstream (i.e get it included in the kernel)

[bistory]

Originally Posted by guillaumezin

Well, because I wasn't aware that there was already one, like a lot of people here: https://bugs.launchpad.net/ubuntu/+s...il/+bug/345531

Maybe there's a way to adapt your driver to eat less cpu ? I didn't test the MacTel driver, so I'm not able to say if it eats less CPU ^^

[guillaumezin]

Originally Posted by Dragoran

The correct way here is to send your driver upstream (i.e get it included in the kernel)

Well, yes and no, I wrote this driver to enhance the proprietary driver that doesn't handle the backlight, my idea is that it should be distributed with the video closed source driver. But I will enhance it and if it is good enough, I will propose it for kernel inclusion.

Guillaume

[guillaumezin]

Hello,

The driver has been updated. Please see the initial post.

Guillaume.

[bistory]

Here are the files needed for you to autoload

Thanks again for your work

[bistory]

You missed one dkms in the install command :
sudo tar xvjf nvidia_bl-0.50.tar.bz2 -C /usr/src --exclude *.deb && sudo dkms add build install -m nvidia_bl -v 0.50

Anyway, I tested it and it works perfectly