setpci(8) The PCI Utilities setpci(8)
setpci - configure PCI devices
setpci [options] devices operations...
setpci is a utility for querying and configuring PCI devices.
All numbers are entered in hexadecimal notation.
-v Tells setpci to be verbose and display detailed information
about configuration space accesses.
-f Tells setpci not to complain when there’s nothing to do (when no
devices are selected). This option is intended for use in
widely-distributed configuration scripts where it’s uncertain
whether the device in question is present in the machine or not.
-D ‘Demo mode’ -- don’t write anything to the configuration regis-
ters. It’s useful to try setpci -vD to see what your complex
sequence of setpci operations does before you actually execute
Shows setpci version. This option should be used stand-alone.
Before each sequence of operations you need to select which devices you
wish that operation to affect.
Show only devices in the specified domain (in case your machine
has several host bridges, they can either share a common bus
number space or each of them can address a PCI domain of its
own; domains are numbered from 0 to ffff), bus (0 to ff), slot
(0 to 1f) and function (0 to 7). Each component of the device
address can be omitted or set to "*", both meaning "any value".
All numbers are hexadecimal. E.g., "0:" means all devices on
bus 0, "0" means all functions of device 0 on any bus, "0.3"
selects third function of device 0 on all buses and ".4" shows
only the fourth function of each device.
Select devices with specified vendor and device ID. Both ID’s
are given in hexadecimal and may be omitted or given as "*",
both meaning "any value".
To query value of a configuration register, just name it (either by
typing its name or by typing register address with optional .B, .W or
.L suffix specifying register width as byte, word or longword).
To set a register, write reg=values where reg is the same as you would
use to query the register and values is a comma-separated list of val-
ues you want to write starting with the given address. Each value to be
written can be specified either as a hexadecimal number or as a
bits:mask pair which causes the bits corresponding to binary ones in
the mask to be changed to values of the corresponding bits in the bits
setpci knows the following configuration register names. See PCI bus
specs for their precise meaning or consult /usr/include/linux/pci.h for
The PCI utilities use PCILIB (a portable library providing platform-
independent functions for PCI configuration space access) to talk to
the PCI cards. The following options control parameters of the library,
especially what access method it uses. By default, PCILIB uses the
first available access method and displays no debugging messages. Each
switch is accompanied by a list of hardware/software configurations
it’s supported in.
Force use of Linux /proc/bus/pci style configuration access,
using <dir> instead of /proc/bus/pci. (Linux 2.1 or newer only)
-H1 Use direct hardware access via Intel configuration mechanism 1.
(i386 and compatible only)
-H2 Use direct hardware access via Intel configuration mechanism 2.
Warning: This method is able to address only first 16 devices on
any bus and it seems to be very unreliable in many cases. (i386
and compatible only)
Extract all information from given file containing output of
lspci -x. This is very useful for analysis of user-supplied bug
reports, because you can display the hardware configuration in
any way you want without disturbing the user with requests for
more dumps. (All systems)
-G Increase debug level of the library. (All systems)
‘setpci -d *:* latency_timer=40’ sets the latency timer to 64 (40 hex-
‘setpci -s 0 device_id vendor_id’ lists ID’s of devices in slot 0 in
‘setpci -s 12:3.4 3c.l=1,2,3’ writes longword 1 to register 3c, 2 to
register 3d and 3 to register 3e of device at bus 12, slot 3, function
‘setpci -s 13:8.4 40.b=50:d0,04:0c,ff’ works on bus 13, device 8, func-
tion 4: turns bit 7 off and bits 6 and 4 on in the byte register 40;
turns bit 3 off and bit 2 on in the byte register 41; sets byte regis-
ter 42 to ff.
The PCI Utilities are maintained by Martin Mares <firstname.lastname@example.org>.
pciutils-2.1.99-test8 13 August 2004 setpci(8)
Man(1) output converted with