From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arek Burdach Subject: Re: Missing release event for Synaptics touchscreen Date: Fri, 12 May 2017 09:25:16 +0200 Message-ID: <27a556e7-2045-2d6a-3b13-287d314375d5@gmail.com> References: <708339c2-2b70-81ae-a939-ac122e5fd6f2@gmail.com> <09314823-31c8-5855-d55c-3427b58b42ca@gmail.com> <1f16ba27-99cd-d16d-f09f-97dcda1bd358@gmail.com> <03d13b14-1f97-eee7-4131-60ef014cbf50@gmail.com> <8c492623-d37c-e8e1-2445-cf86109dad44@ginzinger.com> <9e370d9b-a2d4-9fcd-9b0d-2d97e225188a@ginzinger.com> <8566ae03-faad-a1ee-2156-db49d36cea71@ginzinger.com> <540cd246-d72f-a9eb-9618-ff2449384a21@ginzinger.com> <8d690a3d-88f6-cef9-b271-da5dcc87741b@gmail.com> <12ac2e90-ba7b-8a29-bb35-40d50841a63b@ginzinger.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wm0-f65.google.com ([74.125.82.65]:33108 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757000AbdELHZU (ORCPT ); Fri, 12 May 2017 03:25:20 -0400 Received: by mail-wm0-f65.google.com with SMTP id y10so11885148wmh.0 for ; Fri, 12 May 2017 00:25:19 -0700 (PDT) In-Reply-To: <12ac2e90-ba7b-8a29-bb35-40d50841a63b@ginzinger.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Martin Kepplinger , Benjamin Tissoires Cc: Andrew Duggan , =?UTF-8?Q?St=c3=a9phane_Chatty?= , linux-input On 12.05.2017 08:56, Martin Kepplinger wrote: >>>>>> No, you won't have "move after hold>5s" broken. Because at the HID >>>>>> level, the device is supposed to send an update on every touch when >>>>>> reporting a touch (for Windows 8 devices). So if there are tiny >>>>>> movements filtered at the input level in the kernel, we will get those >>>>>> and I suspect the timeout will only appear when the finger actual >>>>>> leaves the surface. >>>>> ok. sounds a little more like a solution in the kernel would be >>>>> justified. Isn't it? It still feels dangerously ugly. >>>>> >>>>> Mainly I wanted to point out that if you somehow have to stay with "no" >>>>> for such broken devices, tslib would be a garbage can for userspace >>>>> workarounds. (in this case, most probably a new device-specific hidraw >>>>> based module). > (...) > >> Thank you for clarification. So do someone have an idea how it is >> possible that Windows manages this? From my point of view, they can't >> rely on timeouts because effect is visible immediately after releasing >> finger. Is it possible that they use other protocol for communication >> with device then we do? Because beside that, I don't see any other >> option - there is too few information from device to correctly handle >> this situation. > hey, Benjamin explained what most probably is going on, see above, so: > > 1. convice yourself that microsoft isn't using out-of-band data by > sniffing the connection. Touchscreen is communicating via i2c - am i right? Can you recommend some i2c sniffer for windows? > 2. if not, and Benjamin is right, come up with a timer- and hidraw based > solution (I guess) and convince him and Dmitry to take it. > > 3. if they don't see any chance to support such broken behaviour in the > kernel, which could as well be and also has it's benefits in some way, > you write the thing in userspace (a tslib raw module is only one example > that would make it easy for you). > > Even *if* Synaptics would come up with a firmware update: > 1. the current firmware is already out there in the wild; > 2. it takes time and work to get people to update > > so, if I had the device, I'd write a workaround. It is reasonable what you've wrote. The only blocker for me is that I have almost zero-experience in low level programming. I'm from java world :-) It is why I was looking for some low entry level solution. I'll do my best but every helping hand will be appreciated. Cheers, Arek