• Dmitry Torokhov's avatar
    Input: i8042 - disable active multiplexing by default · 68da1664
    Dmitry Torokhov authored
    Active multiplexing is a nice feature as it allows several pointing devices
    (such as touchpad and external mouse) use their native protocols at the
    same time. Unfortunately many manufacturers do not implement the feature
    properly even though they advertise it. The problematic implementations are
    never fixed, since Windows by default does not use this mode, and move from
    one BIOS/model of laptop to another. When active multiplexing is broken
    turning it on usually results in touchpad, keyboard, or both unresponsive.
    
    With PS/2 usage on decline (most of PS/2 devices in use nowadays are
    internal laptop touchpads), I expect number of users who have laptops with
    working MUX implementation, docking stations with external PS/2 ports, and
    who are still using external PS/2 mice, to be rather small. Let's flip the
    default to be OFF and allow activating it through i8042.nomux=0 kernel
    option.  We'll also keep DMI table where we can record known good models.
    Acked-by: default avatarJiri Kosina <jkosina@suse.cz>
    Acked-by: default avatarHans de Goede <hdegoede@redhat.com>
    Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
    68da1664
i8042.c 33.6 KB