From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758574AbeBPQjH (ORCPT ); Fri, 16 Feb 2018 11:39:07 -0500 Received: from mail-wr0-f176.google.com ([209.85.128.176]:34677 "EHLO mail-wr0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752318AbeBPQjF (ORCPT ); Fri, 16 Feb 2018 11:39:05 -0500 X-Google-Smtp-Source: AH8x226hY7onqTUQ9oj6LF9qQJsCTNmaW0+3CmPs5YwK1/LmxPUOcpB1aijROyS4RVR6lJRQW+YzLjezjZn8ABrHZFQ= MIME-Version: 1.0 In-Reply-To: <5bfec26e-b09c-2fa0-4eb0-3f9a08d293ed@ginzinger.com> References: <1493295756-17812-1-git-send-email-martin.kepplinger@ginzinger.com> <5bfec26e-b09c-2fa0-4eb0-3f9a08d293ed@ginzinger.com> From: Christian Gmeiner Date: Fri, 16 Feb 2018 17:38:43 +0100 Message-ID: Subject: Re: [PATCH 1/2] input: touchscreen: ar1021_i2c: enable touch mode during open To: Martin Kepplinger Cc: Dmitry Torokhov , linux-input , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2018-02-05 11:40 GMT+01:00 Martin Kepplinger : > > > > > Martin Kepplinger | Entwicklung Software > > GINZINGER ELECTRONIC SYSTEMS GMBH > > Tel.: +43 7723 5422 157 > Mail: martin.kepplinger@ginzinger.com > Web: www.ginzinger.com > > > > > On 2018-02-05 11:07, Christian Gmeiner wrote: >> Hi all. >> >> 2017-04-27 14:22 GMT+02:00 Martin Kepplinger : >>> The device could as well be in command mode, in which this driver cannot >>> handle the device. When opening the device, let's make sure the device >>> will be in the mode we expect it to be for this driver. >>> >> >> I run into issues caused by this change. It turns out that the device >> is non-functional >> after some warm-reboots and as a result I am not able to use xorg's >> evdev driver. >> So I have some questions about this change: >> >> * Should we enable irq before calling i2c_master_send(..) as the chip raises an >> irq if the command was processed? >> >> * Would it be enough to send this command only once during driver >> lifetime? I can >> see that on my system open gets called 3 times during boot-up. > > It would. See below for my thought on this change. > >> >> * What are the circumstances the touch device would be in an other state? In the >> official kernel driver the userspace can send commands via sysfs. >> Also the driver >> does set the touch enable mode as this patch does. > > I did this change as the device was once non-functional unexpectedly > because it wasn't in touch mode. We can set touch mode during open() or > probe() but I figured during open() would keep the driver working even > when others would use the device in command mode. > > Does your problem go away when you revert this change or put it into > probe()? I needed to postprone further research and reverted this commit locally as a new software release gets releases soon. The good this that I have an automated way to run a test to trigger this issue quite easily. Will have a deeper look after release time. -- greets -- Christian Gmeiner, MSc https://christian-gmeiner.info