• Masaki Ota's avatar
    Input: ALPS - fix two-finger scroll breakage in right side on ALPS touchpad · 4a646580
    Masaki Ota authored
    Fixed the issue that two finger scroll does not work correctly
    on V8 protocol. The cause is that V8 protocol X-coordinate decode
    is wrong at SS4 PLUS device. I added SS4 PLUS X decode definition.
    
    Mote notes:
    the problem manifests itself by the commit e7348396 ("Input: ALPS
    - fix V8+ protocol handling (73 03 28)"), where a fix for the V8+
    protocol was applied.  Although the culprit must have been present
    beforehand, the two-finger scroll worked casually even with the
    wrongly reported values by some reason.  It got broken by the commit
    above just because it changed x_max value, and this made libinput
    correctly figuring the MT events.  Since the X coord is reported as
    falsely doubled, the events on the right-half side go outside the
    boundary, thus they are no longer handled.  This resulted as a broken
    two-finger scroll.
    
    One finger event is decoded differently, and it didn't suffer from
    this problem.  The problem was only about MT events. --tiwai
    
    Fixes: e7348396 ("Input: ALPS - fix V8+ protocol handling (73 03 28)")
    Signed-off-by: default avatarMasaki Ota <masaki.ota@jp.alps.com>
    Tested-by: default avatarTakashi Iwai <tiwai@suse.de>
    Tested-by: default avatarPaul Donohue <linux-kernel@PaulSD.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
    4a646580
alps.c 85.5 KB