setpci(8) Linux PCI Utilities setpci(8)
setpci - configure PCI devices
setpci [options] devices operations...
setpci is a utility for querying and configuring PCI devices.
To make use of all the features of this program, you need to have Linux
kernel 2.1.82 or newer which supports the /proc/bus/pci interface. With
older kernels, the PCI utilities have to use direct hardware access
which is available only to root and it suffers from numerous race con-
ditions and other problems.
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' -- simulate configuration space accesses instead of
really doing them. It's useful to try setpci -vD to see what
your complex sequence of setpci operations does before you actu-
ally execute it.
Shows setpci version. This option should be used standalone.
Before each sequence of operations you need to select which devices you
wish that operation to affect.
Select devices in specified bus, slot and function. Each compo-
nent of the device address can be omitted or set as "*" 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 busses and
".4" selects only 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 "*"
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 you would use
to query the register and values is a comma-separated list of values
you want to write starting with the given address.
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.
Use Linux 2.1 style configuration access to directory <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 unrealiable in many cases. (i386
and compatible only)
-S Use PCI access syscalls. (Linux on Alpha and UltraSparc 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
The Linux PCI Utilities are maintained by Martin Mares <email@example.com>.
pciutils-2.1.10 30 March 2002 setpci(8)