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DEVCTL(8) FreeBSD System Manager's Manual DEVCTL(8)
NAME
devctl - device control utility
SYNOPSIS
devctl attach device
devctl clear driver [-f] device
devctl detach [-f] device
devctl disable [-f] device
devctl enable device
devctl suspend device
devctl resume device
devctl set driver [-f] device driver
devctl rescan device
devctl delete [-f] device
devctl freeze
devctl thaw
devctl reset [-d] device
devctl getpath locator device
DESCRIPTION
The devctl utility adjusts the state of individual devices in the
kernel's internal device hierarchy. Each invocation of devctl consists
of a single command followed by command-specific arguments. Each command
operates on a single device specified via the device argument. The
device may be specified either as the name of an existing device or as a
bus-specific address. More details on supported address formats can be
found in devctl(3).
The following commands are supported:
attach device
Force the kernel to re-probe the device. If a suitable driver is
found, it is attached to the device.
detach [-f] device
Detach the device from its current device driver. If the -f flag
is specified, the device driver will be detached even if the
device is busy.
disable [-f] device
Disable a device. If the device is currently attached to a
device driver, the device driver will be detached from the
device, but the device will retain its current name. If the -f
flag is specified, the device driver will be detached even if the
device is busy.
enable device
Enable a device. The device will probe and attach if a suitable
device driver is found. Note that this can re-enable a device
disabled at boot time via a loader tunable.
suspend device
Suspend a device. This may include placing the device in a
reduced power state.
resume device
Resume a suspended device to a fully working state.
not specified, the device will not be changed.
clear driver [-f] device
Clear a previously-forced driver name so that the device is able
to use any valid device driver. After the previous name has been
cleared, the device is reprobed so that other device drivers may
attach to it. This can be used to undo an earlier set driver
command. If the device is currently attached to a device driver
and the -f flag is not specified, the device will not be changed.
rescan device
Rescan a bus device checking for devices that have been added or
removed.
delete [-f] device
Delete the device from the device tree. If the -f flag is
specified, the device will be deleted even if it is physically
present. This command should be used with care as a device that
is deleted but present can no longer be used unless the parent
bus device rediscovers the device via a rescan request.
freeze Freeze probe and attach processing initiated in response to
drivers being loaded. Drivers are placed on a "frozen list" and
processed when a later "thaw" occurs.
thaw Resume (thaw the freeze) probe and attach initiated in response
to drivers being loaded. In addition to resuming, all pending
actions that were frozen during the freeze are performed.
reset [-d] device
Reset the device, using bus-specific reset method. Drivers for
the devices being reset are suspended around the reset. If the
-d option is specified, drivers are detached instead.
Currently, resets are implemented for PCIe buses and PCI devices.
For PCIe bus, the link is disabled and then re-trained, causing
all children of the bus to reset. Use -p option of devinfo(8)
tool to report parent bus for the device. For PCI device, if
Function-Level Reset is implemented by it, FLR is tried first; if
failed or not implemented, power reset is tried.
If you have detached or suspended a child device explicitly and
then do a reset, the child device will end up attached.
getpath locator device
Prints the full path to the device using the locator method to
get the path name. Currently, only the "UEFI" and "FreeBSD"
locators are implemented. The UEFI locator constructs a path to
the device using the rules outlines for DEVICE_PATH in the UEFI
standard. The FreeBSD locator constructs a path back to the root
of the tree with the nodes separated by slashes.
SEE ALSO
devctl(3), devinfo(8)
HISTORY
The devctl utility first appeared in FreeBSD 10.3.
BUGS