• Dmitry Torokhov's avatar
    HID: input: fix battery level reporting on BT mice · 2e210bbb
    Dmitry Torokhov authored
    The commit 581c4484 ("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: 581c4484 ("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: default avatarMartin van Es <martin@mrvanes.com>
    Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
    Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
    2e210bbb
hid-input.c 50 KB