Screen Preferences - bright slider don't work on Intel GMA (i945GME)

[bruno]

Hi. I have a laptop with an Intel graphics card. See https://dev.haiku-os.org/ticket/16341 for referencxe...

Haiku nightly 32bit hrev: 55795

Intel Atom 1.60 GHz

~> listimage | grep accel
 2494 0x01676000 0x0168f000     0          0 /boot/home/config/non-packaged/add-ons/accelerants/intel_extreme.accelerant

Haiku identify that as GMA (GM45) in the Screen Preferences. The actual Intel driver works well, but unfortunatelly, the bright control don't work. I can move the slide to either side, but the screen bright keep in the same level. (See Bug #16341)

device Display controller [3|80|0]
  vendor 8086: Intel Corporation
  device 27a6: Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller

device Display controller (VGA compatible controller, VGA controller) [3|0|0]
  vendor 8086: Intel Corporation
  device 27ae: Mobile 945GSE Express Integrated Graphics Controller

[humdinger]

From the listimage output, it appears you have a driver installed in ~/config/non-packaged. Maybe a leftover from some older build? I'd say, remove it and see if the system provided driver works.

[bruno]

1stupid me... yes I forgot to delete the experimental Driver from Rudolph.. anyways, still not working brightness slider

Here my actual accel grep: listimage | grep accel

2492 0x00366000 0x00384000 0 0 /boot/system/add-ons/accelerants/intel_extreme.accelerant

TEAM 623 (/bin/grep --color=auto accel):

[pulkomandy]

Can you enter KDL (use Alt+PrintScreen+d or use the kernel_debugger command in terminal) and type the following commands:

ie_reg 0x61254
ie_reg 0x61354

And give us the results?

You can use the "continue" command to exit from KDL.

---

Technical details for other devs looking at this bugreport:

There seem to be two different backlight control registers for these old Intel graphics generations, one for each pipe. We are always using the one for pipe A currently. Maybe this machine needs the one on pipe B?

If this doesn't work, I assume the backlight is driven in some other way. In that case, maybe the acpi display driver will be of more help.

[bruno]

Hello Pulkomandy, here is the output from KDL:

ie_reg 0x61254: intel extreme register 0x61254 output: value: 0x2 (2)

ie_reg 0x61354: intel extreme register 0x61354 output: value: 0x0 (0)

hope it helps

[pulkomandy]

Hello,

Does it work better with hrev56036 or later or is it still the same?

[pulkomandy]

It's also possible that ​https://review.haiku-os.org/c/haiku/+/5227 will help?

[bruno]

Does it work better with hrev56036 or later or is it still the same?

It is still the same!