Brightness adjustment of screen backlights in Ubuntu Linux

There are many ways to adjust the brightness of the laptop screen in Ubuntu Linux. Some adjust the brightness but not the backlight brightness, and some adjust the backlight brightness on my computer ...... I have found this method for a long time. It should be widely used (at least I can use it here ).

First, enter the terminal and enter the lspci command to list the addresses of various devices.

Www.linxidc.com @ Ubuntu :~ $ Lspci
. 0 host bridge: Intel Corporation mobile 945gm/PM/GMS, 943/940 GML and 945gt express memory controller Hub (Rev 03)

. 0 VGA compatible Controller: Intel Corporation mobile 945gm/GMS, 943/940 GML express integrated graphics controller (Rev 03)
. 1 display controller: Intel Corporation mobile 945gm/GMS/GME, 943/940 GML express integrated graphics controller (Rev 03)
00: 1b. 0 audio device: Intel Corporation N10/ich 7 family high definition Audio Controller (Rev 02)
00: 1C. 0 PCI Bridge: Intel Corporation N10/ich 7 family PCI Express Port 1 (Rev 02)
00: 1C. 1 PCI Bridge: Intel Corporation N10/ich 7 family PCI Express Port 2 (Rev 02)
......

We found. 0 was a VGA device, so we modified its properties.

Sudo setpci-s 00:02. 0 f4. B = FF

Explanations:

Setpci is the command for modifying device properties.
-S indicates that the device address is entered next.
. 0 VGA device address (<bus >:< interface>. <function>)
The address of the property to be modified by F4, which indicates "brightness"
. B modified length (B should be byte, w (should be word, two bytes), L (should be long, four bytes ))
= FF value to be modified (can be changed)

Here, 00 is the lowest, FF is the brightest, and different computers may be different.

For example, if FF is too eye-catching, I can sudo setpci-S. 0 f4. B = cc, it will be a bit darker.