7a2f2974f2
Commit 88b7381a939d ("USB: Select better matching USB drivers when
available") introduced the use of a "match" function to select a
non-generic/better driver for a particular USB device. This
unfortunately breaks the operation of usbip in general, as reported in
the kernel bugzilla with bug 208267 (linked below).
Upon inspecting the aforementioned commit, one can observe that the
original code in the usb_device_match function used to return 1
unconditionally, but the aforementioned commit makes the usb_device_match
function use identifier tables and "match" virtual functions, if either of
them are available.
Hence, this commit implements a match function for usbip that
unconditionally returns true to ensure that usbip is functional again.
This change has been verified to restore usbip functionality, with a
v5.7.y kernel on an up-to-date version of Qubes OS 4.0, which uses
usbip to redirect USB devices between VMs.
Thanks to Jonathan Dieter for the effort in bisecting this issue down
to the aforementioned commit.
Fixes: 88b7381a939d ("USB: Select better matching USB drivers when available")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208267
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1856443
Link: https://github.com/QubesOS/qubes-issues/issues/5905
Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com>
Cc: <stable@vger.kernel.org> # 5.7
Cc: Valentina Manea <valentina.manea.m@gmail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Reviewed-by: Bastien Nocera <hadess@hadess.net>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200810160017.46002-1-m.v.b@runbox.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.