[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Bug#927091: linux-image-5.0.0-trunk-amd64: Broken scrollwheel after upgrade


I bisected the kernel to the following commit:

2dc702c991e3774af9d7ce410eef410ca9e2357e is the first bad commit
commit 2dc702c991e3774af9d7ce410eef410ca9e2357e
Author: Peter Hutterer <peter.hutterer@who-t.net>
Date:   Wed Dec 5 10:42:24 2018 +1000

    HID: input: use the Resolution Multiplier for high-resolution scrolling

    Windows uses a magic number of 120 for a wheel click. High-resolution
    scroll wheels are supposed to use a fraction of 120 to signal smaller
    scroll steps. This is implemented by the Resolution Multiplier in the
    device itself.

    If the multiplier is present in the report descriptor, set it to the
    logical max and then use the resolution multiplier to calculate the
    high-resolution events. This is the recommendation by Microsoft, see

    Note that all mice encountered so far have a logical min/max of 0/1, so
    it's a binary "yes or no" to high-res scrolling anyway.

    To make userspace simpler, always enable the REL_WHEEL_HI_RES bit. Where
    the device doesn't support high-resolution scrolling, the value for the
    high-res data will simply be a multiple of 120 every time. For
    if REL_WHEEL_HI_RES is available that is the one to be used.

    Potential side-effect: a device with a Resolution Multiplier applying to
    other Input items will have those items set to the logical max as well.
    This cannot easily be worked around but it is doubtful such devices

    Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
    Verified-by: Harry Cutts <hcutts@chromium.org>
    Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

:040000 040000 fc4c9b48f3723ef6a8f36b768308bb3c99c9f882
475d4548b75765df6447e43992b07259b181f515 M	drivers
:040000 040000 dc356f23227a874721e6688445fc2b90f726e2a7
2190e33e4ad1bcaff0b35dc03194f29fbd9493c6 M	include

Reply to: