我在我的电脑上安装了 Fedora Linux 35iMac（21.5"，2009 年末）。它工作正常，只是我无法通过键盘（Apple 自己的键盘）快捷键或 Fedora 本身内的滑块控制屏幕亮度。我可以看到屏幕变化的视觉提示但实际亮度并没有改变。
这是有关我的系统的一些信息。
uname -r：
5.16.15-201.fc35.x86_64
lspci：
00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 18)
00:01.0 PCI bridge: Intel Corporation Core Processor PCI Express x16 Root Port (rev 18)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB Universal Host Controller (rev 06)
00:1a.7 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 06)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 06)
00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 06)
00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 06)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB Universal Host Controller (rev 06)
00:1d.7 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev a6)
00:1f.0 ISA bridge: Intel Corporation P55 Chipset LPC Interface Controller (rev 06)
00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 6 port SATA AHCI Controller (rev 06)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 06)
00:1f.6 Signal processing controller: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem (rev 06)
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV730/M96-XT [Mobility Radeon HD 4670]
01:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] RV710/730 HDMI Audio [Radeon HD 4000 series]
02:00.0 Ethernet controller: Broadcom Inc. and subsidiaries NetXtreme BCM5764M Gigabit Ethernet PCIe (rev 10)
03:00.0 Network controller: Qualcomm Atheros AR928X Wireless Network Adapter (PCI-Express) (rev 01)
04:00.0 PCI bridge: Texas Instruments XIO2213A/B/XIO2221 PCI Express to PCI Bridge [Cheetah Express] (rev 01)
05:00.0 FireWire (IEEE 1394): Texas Instruments XIO2213A/B/XIO2221 IEEE-1394b OHCI Controller [Cheetah Express] (rev 01)
ff:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers (rev 05)
ff:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 05)
ff:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 05)
ff:02.1 Host bridge: Intel Corporation 1st Generation Core i3/5/7 Processor QPI Physical 0 (rev 05)
ff:02.2 Host bridge: Intel Corporation 1st Generation Core i3/5/7 Processor Reserved (rev 05)
ff:02.3 Host bridge: Intel Corporation 1st Generation Core i3/5/7 Processor Reserved (rev 05)
xrandr：
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080
default connected primary 1920x1080+0+0 0mm x 0mm
1920x1080 77.00*
许多其他人也遇到了类似的问题。有人说这是一个内核问题，其他人提供了解决方案。我尝试了其中一些解决方案，例如这一个但没有用。
有任何想法吗？