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There are some ABI documents that, while they don't generate any warnings, they have issues when parsed by get_abi.pl script on its output result. Address them, in order to provide a clean output. Reviewed-by: Tom Rix <trix@redhat.com> # for fpga-manager Reviewed-By: Kajol Jain<kjain@linux.ibm.com> # for sysfs-bus-event_source-devices-hv_gpci and sysfs-bus-event_source-devices-hv_24x7 Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for IIO Acked-by: Oded Gabbay <oded.gabbay@gmail.com> # for Habanalabs Acked-by: Vaibhav Jain <vaibhav@linux.ibm.com> # for sysfs-bus-papr-pmem Acked-by: Cezary Rojewski <cezary.rojewski@intel.com> # for catpt Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Ilya Dryomov <idryomov@gmail.com> # for rbd Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/5bc78e5b68ed1e9e39135173857cb2e753be868f.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1.8 KiB
1.8 KiB
What: /sys/bus/pci/drivers/ehci_hcd/.../companion /sys/bus/usb/devices/usbN/../companion Date: January 2007 KernelVersion: 2.6.21 Contact: Alan Stern stern@rowland.harvard.edu Description: PCI-based EHCI USB controllers (i.e., high-speed USB-2.0 controllers) are often implemented along with a set of "companion" full/low-speed USB-1.1 controllers. When a high-speed device is plugged in, the connection is routed to the EHCI controller; when a full- or low-speed device is plugged in, the connection is routed to the companion controller.
Sometimes you want to force a high-speed device to connect
at full speed, which can be accomplished by forcing the
connection to be routed to the companion controller.
That's what this file does. Writing a port number to the
file causes connections on that port to be routed to the
companion controller, and writing the negative of a port
number returns the port to normal operation.
For example: To force the high-speed device attached to
port 4 on bus 2 to run at full speed::
echo 4 >/sys/bus/usb/devices/usb2/../companion
To return the port to high-speed operation::
echo -4 >/sys/bus/usb/devices/usb2/../companion
Reading the file gives the list of ports currently forced
to the companion controller.
Note: Some EHCI controllers do not have companions; they
may contain an internal "transaction translator" or they
may be attached directly to a "rate-matching hub". This
mechanism will not work with such controllers. Also, it
cannot be used to force a port on a high-speed hub to
connect at full speed.
Note: When this file was first added, it appeared in a
different sysfs directory. The location given above is
correct for 2.6.35 (and probably several earlier kernel
versions as well).