Kernel 5.7rc1 is released, and it can be downloaded @ https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.7-rc1/
There are some changes related to amd backlight from 5.6 to 5.7rc1 such as the following (list may be not completed), and it surely worthwhile to give 5.7rc1 a try. accde06fcb7fd82abdfa77ecf4dc63d724a6d9bf 945628101be55833a63355510d4b6c934183deab 8a683eb6311a03b655ab8ff368cd7b203074275c cb8348fec250e517b5facb4cab3125ddc597f9aa -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1861925 Title: BrightnessOutofRange: Actual brightness for amdgpu_bl0 not in range 0..255 Status in linux package in Ubuntu: Incomplete Bug description: Hi, I have a acer aspire a315-41 laptop, it has BIOS 1.15, Ubuntu 19.10, Kernel stock 5.3, and 5.5.0. I have a problem with the Backlight. I can not control. According to: https://wiki.ubuntu.com/Kernel/Debugging/Backlight It is : Backlight control does not work, but there are entries in /sys/class/backlight. The problem is as far I could find: sanya@Aspire-A315-41:/sys/class/backlight/amdgpu_bl0$ cat brightness 135 sanya@Aspire-A315-41:/sys/class/backlight/amdgpu_bl0$ cat actual_brightness 43500 sanya@Aspire-A315-41:/sys/class/backlight/amdgpu_bl0$ cat max_brightness 255 The brightness read from the HW is not in the range, and when I change the brightness by the keys the value in the brightness file changes too, but the actual_brightness is stuck at the value 43500... I have tried all the steps mentioned in https://wiki.ubuntu.com/Kernel/Debugging/Backlight Actually I have tried all these kernel startup parameter variants without luck: GRUB_CMDLINE_LINUX_DEFAULT="" #GRUB_CMDLINE_LINUX_DEFAULT="video.use_native_backlight=1" #GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi=" #GRUB_CMDLINE_LINUX_DEFAULT="video.use_bios_initial_backlight=0" #GRUB_CMDLINE_LINUX_DEFAULT="amdgpu.dcfeaturemask=0x4 amdgpu.abmlevel=2" #GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=video amdgpu.abmlevel=1" #GRUB_CMDLINE_LINUX_DEFAULT="i8042.nopnp acpi_osi=Linux acpi_backlight=vendor" #GRUB_CMDLINE_LINUX_DEFAULT="i8042.nopnp acpi_osi=! acpi_osi=\"Windows 2009\" acpi_backlight=vendor" #GRUB_CMDLINE_LINUX_DEFAULT="i8042.nopnp acpi_osi=! acpi_osi=\"Windows 2009\" acpi_backlight=video" #GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi=! acpi_osi=\"Windows 2009\" acpi_backlight=vendor" #GRUB_CMDLINE_LINUX_DEFAULT="i8042.nopnp acpi_osi=! acpi_osi=\"Windows 2009\" acpi_backlight=vendor" #GRUB_CMDLINE_LINUX_DEFAULT="i8042.nopnp acpi_osi=! acpi_osi=\"Windows 2009\" acpi_backlight=vendor" I guess the fwts has found also this as an error: autobrightness: Automated LCD brightness test. -------------------------------------------------------------------------------- Test 1 of 2: Test for maximum and actual brightness. PASSED: Test 1, Maximum brightness for amdgpu_bl0 is 255 which is sane. FAILED [HIGH] BrightnessOutofRange: Test 1, Actual brightness for amdgpu_bl0 not in range 0..255. Test 2 of 2: Change actual brightness. FAILED [MEDIUM] BrightnessMismatch: Test 2, 256 brightness levels did not match the brightnesss level just set for backlight amdgpu_bl0. The failed brightness levels were: 0-255. It would be great if someone could help set the HW brightness back to the normal range. If you need any more debug files please let me know! Thanks, Regards, Sandor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1861925/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
