PCI: Introduce new device binding path using pci_dev.driver_override

[karo-tx-linux.git] / Documentation / ABI / testing / sysfs-bus-pci

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index a3c5a6685036103e7ec677272acdc4620d0302f6..898ddc4440e6c7d3ebf231f76100000543de4faa 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -250,3 +250,24 @@ Description:
                valid.  For example, writing a 2 to this file when sriov_numvfs
                is not 0 and not 2 already will return an error. Writing a 10
                when the value of sriov_totalvfs is 8 will return an error.
+
+What:          /sys/bus/pci/devices/.../driver_override
+Date:          April 2014
+Contact:       Alex Williamson <alex.williamson@redhat.com>
+Description:
+               This file allows the driver for a device to be specified which
+               will override standard static and dynamic ID matching.  When
+               specified, only a driver with a name matching the value written
+               to driver_override will have an opportunity to bind to the
+               device.  The override is specified by writing a string to the
+               driver_override file (echo pci-stub > driver_override) and
+               may be cleared with an empty string (echo > driver_override).
+               This returns the device to standard matching rules binding.
+               Writing to driver_override does not automatically unbind the
+               device from its current driver or make any attempt to
+               automatically load the specified driver.  If no driver with a
+               matching name is currently loaded in the kernel, the device
+               will not bind to any driver.  This also allows devices to
+               opt-out of driver binding using a driver_override name such as
+               "none".  Only a single driver may be specified in the override,
+               there is no support for parsing delimiters.