4f57cace81
Some devices, particularly the 3DConnexion Spacemouse wireless 3D controllers, return more than just the battery capacity in the battery report. The Spacemouse devices return an additional byte with a device specific field. However, hidinput_query_battery_capacity() only requests a 2 byte transfer. When a spacemouse is connected via USB (direct wire, no wireless dongle) and it returns a 3 byte report instead of the assumed 2 byte battery report the larger transfer confuses and frightens the USB subsystem which chooses to ignore the transfer. Then after 2 seconds assume the device has stopped responding and reset it. This can be reproduced easily by using a wired connection with a wireless spacemouse. The Spacemouse will enter a loop of resetting every 2 seconds which can be observed in dmesg. This patch solves the problem by increasing the transfer request to 4 bytes instead of 2. The fix isn't particularly elegant, but it is simple and safe to backport to stable kernels. A further patch will follow to more elegantly handle battery reports that contain additional data. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Darren Hart <darren@dvhart.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: stable@vger.kernel.org Tested-by: Darren Hart <dvhart@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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.