• Grant Likely's avatar
    HID: input: Fix devices that return multiple bytes in battery report · 4f57cace
    Grant Likely authored
    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: default avatarGrant 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: default avatarDarren Hart <dvhart@infradead.org>
    Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
    4f57cace
hid-input.c 56.6 KB