xref: /OK3568_Linux_fs/kernel/Documentation/ABI/testing/sysfs-bus-vmbus (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunWhat:		/sys/bus/vmbus/devices/.../driver_override
2*4882a593SmuzhiyunDate:		August 2019
3*4882a593SmuzhiyunContact:	Stephen Hemminger <sthemmin@microsoft.com>
4*4882a593SmuzhiyunDescription:
5*4882a593Smuzhiyun		This file allows the driver for a device to be specified which
6*4882a593Smuzhiyun		will override standard static and dynamic ID matching.  When
7*4882a593Smuzhiyun		specified, only a driver with a name matching the value written
8*4882a593Smuzhiyun		to driver_override will have an opportunity to bind to the
9*4882a593Smuzhiyun		device.  The override is specified by writing a string to the
10*4882a593Smuzhiyun		driver_override file (echo uio_hv_generic > driver_override) and
11*4882a593Smuzhiyun		may be cleared with an empty string (echo > driver_override).
12*4882a593Smuzhiyun		This returns the device to standard matching rules binding.
13*4882a593Smuzhiyun		Writing to driver_override does not automatically unbind the
14*4882a593Smuzhiyun		device from its current driver or make any attempt to
15*4882a593Smuzhiyun		automatically load the specified driver.  If no driver with a
16*4882a593Smuzhiyun		matching name is currently loaded in the kernel, the device
17*4882a593Smuzhiyun		will not bind to any driver.  This also allows devices to
18*4882a593Smuzhiyun		opt-out of driver binding using a driver_override name such as
19*4882a593Smuzhiyun		"none".  Only a single driver may be specified in the override,
20*4882a593Smuzhiyun		there is no support for parsing delimiters.
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