setpci

A utility for querying and configuring PCI devices.

Description

The setpci command is a utility used to query and configure PCI devices.

Syntax

setpci [options] [parameters]

Options

-v: Display detailed information about the execution of the command.
-f: Do not display any information when there are no operations to be completed.
-D: Test mode; do not actually write configuration information to the registers.
-d: Display information only for a given vendor and device ID.
-s: Display information only for devices on a specified bus and slot, or function blocks on a device.

Parameters

• PCI Device: Specify the PCI device to be configured.
• Operations: Specify the configuration operations to be completed.

Examples

Method to adjust laptop screen brightness in Linux:

First, enter the lspci command in the terminal to list the addresses of various devices:

lspci
00:00.0 host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML 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 find that 00:02.0 is the VGA device, so we modify its attributes:

sudo setpci -s 00:02.0 F4.B=FF

Explanation:

• setpci: The command to modify device attributes.
• -s: Indicates that the following input is the device address.
• 00:02.0: VGA device address ( : . ).
• F4: The address of the attribute to modify, which represents "brightness" in this case.
• .B: The length of the modification (B for Byte; other options include w for Word (2 bytes) and L for Long (4 bytes)).
• =FF: The value to be set (can be changed).

In this example, 00 is the darkest and FF is the brightest. This may vary for different computers. If FF is too bright, you can use:

sudo setpci -s 00:02.0 F4.B=CC