From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hutterer Subject: [PATCH] HID: logitech: Handle 0 scroll events for the m560 Date: Wed, 20 Mar 2019 08:48:23 +1000 Message-ID: <20190319224823.GA26366@jelly> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: linux-input@vger.kernel.org Cc: Benjamin Tissoires , Aimo =?iso-8859-1?Q?Mets=E4l=E4?= , nlopezcasad@logitech.com, Jiri Kosina , linux-kernel@vger.kernel.org List-Id: linux-input@vger.kernel.org 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 Signed-off-by: Peter Hutterer --- 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