xref: /linux/Documentation/ABI/testing/sysfs-bus-vmbus (revision 3eb66e91a25497065c5322b1268cbc3953642227)
1*d765edbbSStephen HemmingerWhat:		/sys/bus/vmbus/devices/.../driver_override
2*d765edbbSStephen HemmingerDate:		August 2019
3*d765edbbSStephen HemmingerContact:	Stephen Hemminger <sthemmin@microsoft.com>
4*d765edbbSStephen HemmingerDescription:
5*d765edbbSStephen Hemminger		This file allows the driver for a device to be specified which
6*d765edbbSStephen Hemminger		will override standard static and dynamic ID matching.  When
7*d765edbbSStephen Hemminger		specified, only a driver with a name matching the value written
8*d765edbbSStephen Hemminger		to driver_override will have an opportunity to bind to the
9*d765edbbSStephen Hemminger		device.  The override is specified by writing a string to the
10*d765edbbSStephen Hemminger		driver_override file (echo uio_hv_generic > driver_override) and
11*d765edbbSStephen Hemminger		may be cleared with an empty string (echo > driver_override).
12*d765edbbSStephen Hemminger		This returns the device to standard matching rules binding.
13*d765edbbSStephen Hemminger		Writing to driver_override does not automatically unbind the
14*d765edbbSStephen Hemminger		device from its current driver or make any attempt to
15*d765edbbSStephen Hemminger		automatically load the specified driver.  If no driver with a
16*d765edbbSStephen Hemminger		matching name is currently loaded in the kernel, the device
17*d765edbbSStephen Hemminger		will not bind to any driver.  This also allows devices to
18*d765edbbSStephen Hemminger		opt-out of driver binding using a driver_override name such as
19*d765edbbSStephen Hemminger		"none".  Only a single driver may be specified in the override,
20*d765edbbSStephen Hemminger		there is no support for parsing delimiters.
21*d765edbbSStephen Hemminger
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