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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 8CB17C3A59E for ; Wed, 21 Aug 2019 17:54:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C37122CF7 for ; Wed, 21 Aug 2019 17:54:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OdsyLyWI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729365AbfHURy1 (ORCPT ); Wed, 21 Aug 2019 13:54:27 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:37622 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726252AbfHURy1 (ORCPT ); Wed, 21 Aug 2019 13:54:27 -0400 Received: by mail-pf1-f195.google.com with SMTP id y9so1544444pfl.4; Wed, 21 Aug 2019 10:54:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=hQvpuE7ickHKJ52w1YyWzUvO9eTgSHEg1TfmNUoHpDA=; b=OdsyLyWI1H2H3QMzc6Z77+GA50ycKfpclJiY2wLk8LRHGaDuYolz8OU2PDjR7i8uNz PVV99n782kSoXgDZW1867GmbQ2nrY3wHxpduVJyHRzrY4Q9MDncTFdj2ZqUYdL2FQGJj YpxcjBSIxzkd978tpFcxCa53hziyaBAkR/uX5Bs4tuE0qggmQfVwM8rWNNDq2aGdm/F6 fycpM9tJ45oQrC00JoXT05gvP5mpAOrKw5O126Kt9kV/R+KWiSBxdD+fy3R3B33U/axo UxmxH6ff0wOIId/bot7WVXjfOgyH4Z9+ijfbA64RzsyjXwPtc8PrpPDuSzVvp+Qw0tBG ThNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=hQvpuE7ickHKJ52w1YyWzUvO9eTgSHEg1TfmNUoHpDA=; b=YXuPDaRvmwhiSKCgbShAz1J7T5umaUxr8LTaPniByWsiWmcoaomJBq9ukA0t9dw5nH pcCrlhLgOh+iF+FHhCsf0sLvYiEWbPDH4rnpFxqgbD3wk1w5xZrfYwIvFRtvUqYNaXOL b+hSdgGNH2o7lIZqDucXRTjc8maxqq7GG5+s8Hhx03Z0Q0sct59PQSsHXLsG63ixZbTi xxrigeoMp7v4dZo7gXvgudzjfcoxwNjUIhLllJCLUI5ISe2DZacbUCPwLwDzvmZr4+hr +k0q8kf3za4IhwEE/XRXUITsXwaxpkdxZwafc9Fi9xNP8Du/iZEIU8Xr5BfZK3vGu/a+ o+QA== X-Gm-Message-State: APjAAAXPBM4F1Cv/v0tGdLCEZyRD9F+NGYUPITw0uQJZmkncVzxTqW5s 2r+HneMG3rHgTYC6JZ0b6a4= X-Google-Smtp-Source: APXvYqxZtAAOquwUy1cyF0nTstczBGdYuYBRbKInYdAQJKUgKld8r/WXQp12RaKpXD5/FoqNRjyv5A== X-Received: by 2002:a17:90a:21eb:: with SMTP id q98mr1155441pjc.23.1566410066070; Wed, 21 Aug 2019 10:54:26 -0700 (PDT) Received: from dtor-ws ([2620:15c:202:201:3adc:b08c:7acc:b325]) by smtp.gmail.com with ESMTPSA id w26sm28288566pfq.100.2019.08.21.10.54.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Aug 2019 10:54:25 -0700 (PDT) Date: Wed, 21 Aug 2019 10:54:22 -0700 From: Dmitry Torokhov To: Jiada Wang Cc: nick@shmanahar.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, george_davis@mentor.com Subject: Re: [PATCH v1 03/63] Input: atmel_mxt_ts - only read messages in mxt_acquire_irq() when necessary Message-ID: <20190821175422.GE76194@dtor-ws> References: <20190816082952.17985-1-jiada_wang@mentor.com> <20190816082952.17985-4-jiada_wang@mentor.com> <20190816171622.GF121898@dtor-ws> <558e1227-7671-0838-d4e0-f234833c0973@mentor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <558e1227-7671-0838-d4e0-f234833c0973@mentor.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 21, 2019 at 10:26:31PM +0900, Jiada Wang wrote: > Hi Dmitry > > On 2019/08/17 2:16, Dmitry Torokhov wrote: > > On Fri, Aug 16, 2019 at 05:28:52PM +0900, Jiada Wang wrote: > > > From: Nick Dyer > > > > > > The workaround of reading all messages until an invalid is received is a > > > way of forcing the CHG line high, which means that when using > > > edge-triggered interrupts the interrupt can be acquired. > > > > > > With level-triggered interrupts the workaround is unnecessary. > > > > > > Also, most recent maXTouch chips have a feature called RETRIGEN which, when > > > enabled, reasserts the interrupt line every cycle if there are messages > > > waiting. This also makes the workaround unnecessary. > > > > > > Note: the RETRIGEN feature is only in some firmware versions/chips, it's > > > not valid simply to enable the bit. > > > > Instead of trying to work around of misconfiguration for IRQ/firmware, > > can we simply error out of probe if we see a level interrupt with > > !RETRIGEN firmware? > > > I think for old firmwares, which doesn't support RETRIGEN feature, this > workaround is needed, otherwise we will break all old firmwares, which > configured with edge-triggered IRQ Do you know if there are any? I know Chrome OS firmware have RETRIGEN activated and they are pretty old (original Pixel is from 2013). But if we indeed have devices with edge interrupt and old not firmware that does not retrigger, I guess we'll have to keep it... Thanks. -- Dmitry