laptop brightness problem with Slackware current and kernel 4.1.6

af7567 · 08-23-2015, 07:40 AM

Hi, After upgrading my 64bit Slackware current the brightness buttons on my laptop are acting strange as if two programs are managing the brightness and one of them is doing it badly.

I have always used xfce-power-manager for brightness before, and that still seems to be working OK because if I use the brightness slider on the tray icon it works as expected.

Putting values into /sys/class/backlight/acpi_video0/brightness works OK too (which is what I think xfce-power-manager does)

Using the brightness keys on the laptop does update /sys/class/backlight/acpi_video0/brightness properly, but it also flickers the brightness between high and low at the same time and the end result seems random. It could end up extra bright or extra dim whatever the acpi_video0 brightness is set to. This happens even without X running, so I think it is something to do with the kernel but does anyone know what? I would like to stop the kernel changing brightness when I press the brightness buttons if possible and just have it managed by xfce-power-manager like before.

I also have /sys/class/backlight/radeon_bl0 with a brightness and actual_brightness. The actual_brightness seems to randomly go up and down when I use the brightness keys

edit:
I added the radeon.backlight=0 option to my lilo.conf so now the radeon_bl0 is gone from /sys but the brightness still flickers when using the brightness buttons even though the values in acpi_video0 are updating properly. When getting acpi_video0/brightness down to 0 using the buttons the brightness actually displays at about 50%. If using the xfce-power-manager slider or doing echo 0 > brightness the brightness is displayed properly.

oldtechaa · 08-25-2015, 08:00 AM

What is your hardware? What model laptop and what is the output of:

Code:

lspci -nnk

af7567 · 08-25-2015, 08:53 AM

The laptop is a dell studio 1558 with a radeon mobility 5430. lspci -nnk gives

Code:

00:00.0 Host bridge [0600]: Intel Corporation Core Processor DRAM Controller [8086:0044] (rev 18)
	Subsystem: Dell Device [1028:0413]
	Kernel modules: intel_agp
00:01.0 PCI bridge [0604]: Intel Corporation Core Processor PCI Express x16 Root Port [8086:0045] (rev 18)
	Kernel driver in use: pcieport
	Kernel modules: shpchp
00:16.0 Communication controller [0780]: Intel Corporation 5 Series/3400 Series Chipset HECI Controller [8086:3b64] (rev 06)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: mei_me
	Kernel modules: mei_me
00:1a.0 USB controller [0c03]: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller [8086:3b3c] (rev 06)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: ehci-pci
	Kernel modules: ehci_pci
00:1b.0 Audio device [0403]: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio [8086:3b56] (rev 06)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel
00:1c.0 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 [8086:3b42] (rev 06)
	Kernel driver in use: pcieport
	Kernel modules: shpchp
00:1c.1 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 [8086:3b44] (rev 06)
	Kernel driver in use: pcieport
	Kernel modules: shpchp
00:1c.3 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 4 [8086:3b48] (rev 06)
	Kernel driver in use: pcieport
	Kernel modules: shpchp
00:1c.4 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 5 [8086:3b4a] (rev 06)
	Kernel driver in use: pcieport
	Kernel modules: shpchp
00:1c.5 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 6 [8086:3b4c] (rev 06)
	Kernel driver in use: pcieport
	Kernel modules: shpchp
00:1d.0 USB controller [0c03]: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller [8086:3b34] (rev 06)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: ehci-pci
	Kernel modules: ehci_pci
00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev a6)
00:1f.0 ISA bridge [0601]: Intel Corporation Mobile 5 Series Chipset LPC Interface Controller [8086:3b09] (rev 06)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: lpc_ich
	Kernel modules: lpc_ich
00:1f.2 SATA controller [0106]: Intel Corporation 5 Series/3400 Series Chipset 4 port SATA AHCI Controller [8086:3b29] (rev 06)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: ahci
00:1f.3 SMBus [0c05]: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller [8086:3b30] (rev 06)
	Subsystem: Dell Device [1028:0413]
	Kernel modules: i2c_i801
00:1f.6 Signal processing controller [1180]: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem [8086:3b32] (rev 06)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: intel ips
	Kernel modules: intel_ips
02:00.0 VGA compatible controller [0300]: AMD/ATI [Advanced Micro Devices, Inc.] Park [Mobility Radeon HD 5430/5450/5470] [1002:68e0]
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: radeon
	Kernel modules: radeon
02:00.1 Audio device [0403]: AMD/ATI [Advanced Micro Devices, Inc.] Cedar HDMI Audio [Radeon HD 5400/6300 Series] [1002:aa68]
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel
04:00.0 Network controller [0280]: Broadcom Corporation BCM4312 802.11b/g LP-PHY [14e4:4315] (rev 01)
	Subsystem: Dell Wireless 1397 WLAN Mini-Card [1028:000c]
	Kernel driver in use: b43-pci-bridge
	Kernel modules: ssb
07:00.0 SD Host controller [0805]: Ricoh Co Ltd MMC/SD Host Controller [1180:e822] (rev 01)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: sdhci-pci
	Kernel modules: sdhci_pci
07:00.1 System peripheral [0880]: Ricoh Co Ltd R5U2xx (R5U230 / R5U231 / R5U241) [Memory Stick Host Controller] [1180:e230] (rev 01)
	Subsystem: Dell Device [1028:0413]
07:00.3 FireWire (IEEE 1394) [0c00]: Ricoh Co Ltd R5C832 PCIe IEEE 1394 Controller [1180:e832] (rev 01)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: firewire_ohci
	Kernel modules: firewire_ohci
09:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168 PCI Express Gigabit Ethernet controller [10ec:8168] (rev 03)
	Subsystem: Dell Device [1028:0413]
	Kernel driver in use: r8169
	Kernel modules: r8169
ff:00.0 Host bridge [0600]: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers [8086:2c62] (rev 05)
	Subsystem: Intel Corporation Device [8086:8086]
ff:00.1 Host bridge [0600]: Intel Corporation Core Processor QuickPath Architecture System Address Decoder [8086:2d01] (rev 05)
	Subsystem: Intel Corporation Device [8086:8086]
ff:02.0 Host bridge [0600]: Intel Corporation Core Processor QPI Link 0 [8086:2d10] (rev 05)
	Subsystem: Intel Corporation Device [8086:8086]
ff:02.1 Host bridge [0600]: Intel Corporation Core Processor QPI Physical 0 [8086:2d11] (rev 05)
	Subsystem: Intel Corporation Device [8086:8086]
ff:02.2 Host bridge [0600]: Intel Corporation Core Processor Reserved [8086:2d12] (rev 05)
	Subsystem: Intel Corporation Device [8086:8086]
ff:02.3 Host bridge [0600]: Intel Corporation Core Processor Reserved [8086:2d13] (rev 05)
	Subsystem: Intel Corporation Device [8086:8086]

oldtechaa · 08-25-2015, 11:04 AM

I've looked it up and there is this thread about it:
https://bugs.launchpad.net/ubuntu/+s...er/+bug/568611
Another page is this:
http://ubuntuforums.org/showthread.php?t=1184539

First, is your BIOS up-to-date? Someone suggested that could help on a different thread.

Second, what if you try going in the BIOS as per the second thread and mapping the keys differently? Someone got it working with this, at least partially.

Third, was it working in an older release? The first thread suggests it has always been a problem, and may once have been fixed in the kernel, but some people reported the problem returning.

Fourth, try checking dmesg after an attempt to change the brightness with the buttons. Post any output near the end regarding ACPI or brightness or both.

Fifth, try combinations of the following in your kernel parameters:

Code:

dell_laptop.backlight=0 acpi_backlight=vendor radeon.backlight=0

Sixth, read the launchpad bug thread (first link) for anything I might have missed.

Maybe one of these will help. The only other thing I find odd is that on launchpad everyone says they have Intel integrated graphics, but you have a Radeon. I wonder why.

af7567 · 08-25-2015, 02:06 PM

Thanks for your reply. Unfortunately none of these kernel options make a difference. I tried them all together and one at a time but nothing changes, I did reboot and re-run lilo each time I changed them.

I have had slackware on here for a few years and the brightness has always worked fine, it was just with the latest current update that it went wrong when the kernel was updated to 4.1.6.

The brightness control and buttons are still actually working OK using the ACPI interface as it always has done, but there is also another module or something catching the keypresses as well now and causing flickering. I want to disable this module.

There is nothing in dmesg that lets me see what this extra module might be, the only mention of brightness is:

Code:

[Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness

Which was mentioned in the links you posted, but the ACPI brightness interface is the one that is working fine. The BIOS is up to date.

oldtechaa · 08-26-2015, 07:38 AM

You could try a different kernel, I suppose, since it seems that the problem came in some new kernel version. Maybe a 4.0 kernel.

oldtechaa · 08-26-2015, 07:46 AM

You could also try this:

Code:

video.use_native_backlight=1

Also, I found your other thread about your laptop crashing. Did you ever get that fixed?

Nille_kungen · 08-31-2015, 02:32 PM

I also have problem with brightness with radeon but only in KDE.
It works in xfce and from an terminal with "echo 100 > /sys/class/backlight/radeon_bl0/brightness".
I tried an older kernel i have installed but it was the same so i don't think it's the kernel in my case.
I haven't tried with catalyst but i might recompile KDE to see if it solves the problem, but right now i have to little time to play around.
Any tip on what KDE package to recompile?

af7567 · 09-03-2015, 10:25 AM

I still have strange flickering brightness changes when using the brightness buttons, but I just noticed today it only happens when the laptop is plugged into AC power. When running on battery the brightness changes are smooth up and down steps as they should be. On AC it flickers dim then bright on every keypress.

af7567 · 09-03-2015, 10:34 AM

Quote:

Originally Posted by oldtechaa

You could also try this:

Code:

video.use_native_backlight=1

Also, I found your other thread about your laptop crashing. Did you ever get that fixed?

I think I have fixed the laptop crashing problem now. It was caused by 2 things. The biggest problem was whenever my bluetooth mouse went to sleep and disconnected from the system it would result in X doing something that crashed the system and dmesg showed the kernel BUG message in my other post. I "fixed" that by not using my bluetooth USB dongle + mouse anymore.

The other thing sometimes causing the kernel BUG message was conky accessing the hwmon i8k module. This module was never used in previous kernel versions so I blacklisted it now and haven't had a crash since.

Sorry for not replying earlier, I haven't checked back here for a while.