How can i set the screen brightness?

i’m just using intel integrated graphics (i assume that’s what you’re asking)

@PulkoMandy is developing intel video drivers.

so for the time being i’m screwed, right?

Likely so. Lets wait response from video driver developer. Before this please run listdev and listimage kernel in Terminal and paste it here. Also does brightness control work in other OS?

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not listdev:
and yeah, it does

1332 0xffffffff824e7000 0xffffffff824eb000 0 0 /boot/system/add-ons/kernel/drivers/dev/graphics/vesa

VESA fallback driver is used. Your video adapter seems not supported yet.

I made some changes to support brightness control in the VESA driver, but it seems no VESA BIOS actually implements the required calls. So there is nothing to be done from the video driver side. I think however that it’s possible to set the brightness from ACPI in that case. However I have no idea how that works.

When changing the actual brightness of the display isn’t possible, could Haiku fake changing the brightness by having a transparent black overlay that fills the screen, and decreasing the brightness slider would increase the opacity of the overlay? The effect reduces the overall intensity of the display without lowering the backlight brightness. I saw this feature in NomadBSD, and this is just a guess at how it works.

Actually ACPI display brightness isn’t that hard, and most of the hard ACPI driver work is already done:
TODO’s here:


My tablet have this ACPI methods, so brightness control should work when implemented.

I was going to comment about the desirability of laptop display brightness adjustment but see this is already under discussion. Linux (Mint 20.3 in my case) has a power management applet that regulates screen brightness.) Any progress in this area?

Setting screen brightness works for drivers that support it - I think it’s only intel_extreme atm(?)

There’s a slider in the Screen preferences and you can also set it from the command line with the screenmode command.

Here is a (known broken) review for radeon backlights, I don’t have any hardware to test this on, but perhaps another interested party could pick it up.

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Only intel_extreme and only a limited selection of devices (depending on the video card generation, and the way the display is wired to it).

Instead of controlling the hardware directly like this, it should be possible to write a driver using ACPI, which would work on a lot more hardware.


Hello, I tried Beta 3 on my Asus A9RP yesterday, but I don’t have the brightness slider in the Screen control. I started up with failsafe graphics and default resolution. No other kernel parameters were set.
Ok so this A9RP was giving problems a month ago when it refused to switch on, and had to send it to the repair shop. The technician said “chipset problem” and they cannot fix it. But a few days later, when returning the replacement keyboard I bought a few months earlier, it just started up. And after I bought a used Thinkpad T410.:thinking:

It have ATI Radeon Xpress 200M graphics chip. AFAIR brightness ssetting is supported (via the slider in the preflet) only with intel graphics for now.

This can be also the culprit. Have you tested without it?

This should work, try it with Haiku :slight_smile:

Are you sure you used beta3? beta4 is already available, you could use it instead.

Beta 4 cannot boot on this Asus A9RP. It will hang or kdl even with safe mode options enabled. A few times it reached the desktop then the Tracker had an error that hangs the whole system. In Beta 3, the ATI Radeon Xpress 200M is identified by the hardware information application. I haven’t tried any BeOS drivers for ATI cards.

If I boot without any options, the A9RP will hang.
However Haiku Beta 3 works very well on Thinkpad T410i. Even the wifi is detected, and makes everything easier. I also just received a used T400 I bought online a couple of weeks ago, I haven’t tested Haiku on it yet.

ah, then please open a bug report, and possibly test the nightly branch to get this fixed. beta3 is too old by now to reasonably provide support

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