hidpp_scroll_counter_handle_scroll() doesn't expect a 0-value scroll event, it gets interpreted as a negative scroll direction event. This can cause scroll direction resets and thus broken scrolling. Reported-and-tested-by: Aimo Metsälä <aimetsal@xxxxxxxxxxx> Signed-off-by: Peter Hutterer <peter.hutterer@xxxxxxxxx> --- drivers/hid/hid-logitech-hidpp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index 15ed6177a7a3..f040c8a7f9a9 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -2608,8 +2608,9 @@ static int m560_raw_event(struct hid_device *hdev, u8 *data, int size) input_report_rel(mydata->input, REL_Y, v); v = hid_snto32(data[6], 8); - hidpp_scroll_counter_handle_scroll( - &hidpp->vertical_wheel_counter, v); + if (v != 0) + hidpp_scroll_counter_handle_scroll( + &hidpp->vertical_wheel_counter, v); input_sync(mydata->input); } -- 2.20.1
