2e210bbb74
The commit 581c4484769e ("HID: input: map digitizer battery usage")
assumed that devices having input (qas opposed to feature) report for
battery strength would report the data on their own, without the need to
be polled by the kernel; unfortunately it is not so. Many wireless mice
do not send unsolicited reports with battery strength data and have to
be polled explicitly. As a complication, stylus devices on digitizers
are not normally connected to the base and thus can not be polled - the
base can only determine battery strength in the stylus when it is in
proximity.
To solve this issue, we add a special flag that tells the kernel
to avoid polling the device (and expect unsolicited reports) and set it
when report field with physical usage of digitizer stylus (HID_DG_STYLUS).
Unless this flag is set, and we have not seen the unsolicited reports,
the kernel will attempt to poll the device when userspace attempts to
read "capacity" and "state" attributes of power_supply object
corresponding to the devices battery.
Fixes: 581c4484769e ("HID: input: map digitizer battery usage")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=198095
Cc: stable@vger.kernel.org
Reported-and-tested-by: Martin van Es <martin@mrvanes.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.