From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3FF6C0044C for ; Wed, 31 Oct 2018 13:48:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 897412082E for ; Wed, 31 Oct 2018 13:48:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=logitech-com.20150623.gappssmtp.com header.i=@logitech-com.20150623.gappssmtp.com header.b="nSa3TVbX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 897412082E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=logitech.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729366AbeJaWq0 (ORCPT ); Wed, 31 Oct 2018 18:46:26 -0400 Received: from mail-yb1-f193.google.com ([209.85.219.193]:43325 "EHLO mail-yb1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728849AbeJaWqZ (ORCPT ); Wed, 31 Oct 2018 18:46:25 -0400 Received: by mail-yb1-f193.google.com with SMTP id g75-v6so6616339yba.10 for ; Wed, 31 Oct 2018 06:48:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=logitech-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=SClc0V8aqFpX8plRleDD84T0Y58wXcNRcSrkcQr6Mqk=; b=nSa3TVbXVYB7t/HUkXfIk1hMD4Rfn3yBDHk/9D3HX6HZEzqdvp3sf6Sr5uj16Bp6wO EEhpqV+Zq+8LsrTbeoGNPtQxnLXw1c3IzPEczeu/Yg9f17OgYHHKvGts/IJKWXXk8dlJ Aamov5ToQxx2JZZ06cD69ekNNUblJ7/F2jSNilU2tkaWAdW0ZBqRH4/iNo0EDUM1T9ik zEJcZiUm630Z7dcwqV9o0+dV0a6GVJDOHzXp6FakmbXdqshXjLbUKokjhdmhvWQDj8tn NsWAXNjeUkjM/pY7Q8Maog9fbtEO2fCchaim68LK69OJMvHEfOPhHOP5C+T8sqVKCVNg vU2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=SClc0V8aqFpX8plRleDD84T0Y58wXcNRcSrkcQr6Mqk=; b=DAZIVggIIF3F3TagfM+fGHzHalu+J97Hr9nlAYzAG0pDTY7Gs/Zr+XT52Z0KpjQWXZ zxht5SA3fP959P9dFbMBNGgP7ZPiLXOgEplhLWb/kr74TSX4pTXVdGs4AtOjjG9JPCRW /zc4i/XWMXASXb0dDfaJxaqO74VloiTyzawMLUgLUYqn6w71oecE1Rzrffmu5WNXPVvi CDyWKAgD/ftY5kflFAeHTjX4PaGt553cTN5S1MAGlorGySzoe0//FsUjofLefz25Q7Uh xx2+Z/smeICyZa7664WVn/5yEF4R3kl2sD6FddHI8U4Wd9GJIhMKzA2Kp0wnkGIou58q eYow== X-Gm-Message-State: AGRZ1gJLAAZL5gqSp5HJfE60v07OtIr9op0T9Ba/AEi/CpG3w2Opxj4Q lb4n/79qWPL4GMUFNUk9Xjz7iq8EzQszsGlgqyEiFQ== X-Google-Smtp-Source: AJdET5cqXGaB2X92qfZp+GvbVJ7jEHIm2P8R4/vo+V43zLfqub/kh6AgUpEbga6PeA5uO325hz7rZHe37Um/0k92VnQ= X-Received: by 2002:a25:1dc3:: with SMTP id d186-v6mr3018237ybd.485.1540993698802; Wed, 31 Oct 2018 06:48:18 -0700 (PDT) MIME-Version: 1.0 References: <20181030062657.GA5380@jelly> In-Reply-To: From: Nestor Lopez Casado Date: Wed, 31 Oct 2018 14:47:52 +0100 Message-ID: Subject: Re: Logitech high-resolution scrolling.. To: hcutts@chromium.org Cc: Linus Torvalds , peter.hutterer@who-t.net, jikos@kernel.org, Benjamin Tissoires , "open list:HID CORE LAYER" , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi guys, I've read the discussion, I think I understand the problem and I'll get back to this thread with more information as soon as I've got some internal feedback. BTW, lovely to see so many MX Anywhere 2 users :) -nestor On Tue, Oct 30, 2018 at 6:48 PM Harry Cutts wrote: > > Thanks for the analysis, Peter. > > On Mon, 29 Oct 2018 at 23:27, Peter Hutterer w= rote: > > IMO this is a lost battle because you cannot know when the ratchet is > > enabled or not (at least not on all mice). Users switch between ratchet= and > > freewheeling time and once you're out of one mode, you have no referenc= e > > to the other mode's reset point anymore. > > It would be a lost battle, if it weren't for the fact that on all the > mice I've tested, putting the wheel back into clicky mode causes the > wheel to jump to the nearest notch resting point, which should mean > that the remainder resets to 0 (or maybe =C2=B11 if the mechanism is worn= ). > > > So my suggestion is to combine Linus' reset with your approach and use = the > > center-point for the trigger. This gives us a few events to slide and s= till > > do the right thing, and any direction change will reset anyway. Biggest > > drawback is that the first event after a direction change is triggered > > faster than the next event. Otherwise it feels correct to me, both in > > free-wheeling and in ratchet mode now. > > This sounds like a reasonable approach if we find that we can't keep > the triggering point consistent. > > > Also, WTF moment: I managed to get the mouse into a state where it woul= d > > only give me 1 hi-res event per notch movement but failed to reproduce = that > > again. > > Interesting; let me know if you manage to reliably reproduce it. The > only time I've encountered this in the past was when connecting to the > mouse over BLE, where we don't seem to be able to detect if the mouse > is power cycled (meaning that the mouse resets to low-res mode but the > kernel is still expecting high-res reports). I held off on enabling > high-res scrolling over Bluetooth for this reason. > > On Tue, 30 Oct 2018 at 09:29, Linus Torvalds > wrote: > > I wonder if there's some docs on what Logitech does internally in the > > mouse. It might involve a timeout (ie "if not moving for a while, do > > the rounding _and_ reset), which would probably be too expensive to do > > on the host side. > > I've been wondering this as well. Nestor (CCed), is there anything you > can tell us about this? > > Harry Cutts > Chrome OS Touch/Input team