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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 20DF6C433DB for ; Fri, 22 Jan 2021 22:47:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA3F123AAC for ; Fri, 22 Jan 2021 22:47:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728179AbhAVWq6 (ORCPT ); Fri, 22 Jan 2021 17:46:58 -0500 Received: from rere.qmqm.pl ([91.227.64.183]:36765 "EHLO rere.qmqm.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728047AbhAVWqC (ORCPT ); Fri, 22 Jan 2021 17:46:02 -0500 X-Greylist: delayed 465 seconds by postgrey-1.27 at vger.kernel.org; Fri, 22 Jan 2021 17:45:58 EST Received: from remote.user (localhost [127.0.0.1]) by rere.qmqm.pl (Postfix) with ESMTPSA id 4DMvK04gZNz67; Fri, 22 Jan 2021 23:37:24 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rere.qmqm.pl; s=1; t=1611355044; bh=jBEHC8YwgXFlj7D2xiylOBOLQweQ/xz01AF0u5HJYgc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sOnJMs7aWGVRqB43r7lK7L+xxGHSI0L4Azh1+laK91AAUZ4W3ntHePfjxKPQ3qSKv 9brAZZ39Q5L7HFO//yEtamPkPZr9UFvP27QUPSqrhowRjyWg1JAxdMPzWa2x7/O0bB z1YO7nHf/Pj3woUjbrpD0ISvCpEN4Xk7vlGCqfFVRpo8Kz/saSiHlcM1mswfAR3iiz w4Tuz0kqGlKZMZuKLl2k3WmikWmdM5B9InjrST5guVsUKEpWMTY0af8IRhc91Ku9Fh SygDQCc2uLbnrFpADj4Dxa18mKSIHzVIf/aSWelnoIqLrwXdwZOB8DcQbhOVKZlXcg 4FgbkQbYk0Dfw== X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.102.4 at mail Date: Fri, 22 Jan 2021 23:37:18 +0100 From: =?iso-8859-2?Q?Micha=B3_Miros=B3aw?= To: Dmitry Osipenko Cc: Dmitry Torokhov , Johnny Chuang , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format Message-ID: <20210122223718.GE17048@qmqm.qmqm.pl> References: <20201211160917.GA23095@qmqm.qmqm.pl> <3d872d19-a0b2-ed83-4b08-5c9a4755c2fe@gmail.com> <20201211170401.GA31605@qmqm.qmqm.pl> <79cf6571-4239-e98e-6001-70a4bf8b0fe5@gmail.com> <4c443c59-a7f8-bf16-cc0b-0e542c0d127f@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4c443c59-a7f8-bf16-cc0b-0e542c0d127f@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org On Fri, Jan 22, 2021 at 11:10:52PM +0300, Dmitry Osipenko wrote: > 08.01.2021 01:06, Dmitry Osipenko пишет: > > 11.12.2020 21:48, Dmitry Torokhov пишет: > >> On Fri, Dec 11, 2020 at 06:04:01PM +0100, Michał Mirosław wrote: > >>> On Fri, Dec 11, 2020 at 07:39:33PM +0300, Dmitry Osipenko wrote: > >>>> 11.12.2020 19:09, Michał Mirosław пишет: > >>>>> On Thu, Dec 10, 2020 at 11:29:40PM -0800, Dmitry Torokhov wrote: > >>>>>> Hi Michał, > >>>>>> On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: > >>>>>>> @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, void *_dev) > >>>>>>> } > >>>>>>> > >>>>>>> report_len = ts->buf[FW_HDR_LENGTH] / report_count; > >>>>>>> - if (report_len != PACKET_SIZE) { > >>>>>>> + if (report_len != PACKET_SIZE && > >>>>>>> + report_len != PACKET_SIZE_OLD) { > >>>>>>> dev_err(&client->dev, > >>>>>>> - "mismatching report length: %*ph\n", > >>>>>>> + "unsupported report length: %*ph\n", > >>>>>>> HEADER_SIZE, ts->buf); > >>>>>> Do I understand this correctly that the old packets are only observed on > >>>>>> EKTF3624? If so can we expand the check so that we only accept packets > >>>>>> with "old" size when we know we are dealing with this device? > >>>>> > >>>>> We only have EKTF3624 and can't be sure there are no other chips needing this. > >>>> > >>>> In practice this older packet format should be seen only on 3624, but > >>>> nevertheless we could make it more explicit by adding the extra chip_id > >>>> checks. > >>>> > >>>> It won't be difficult to change it in the future if will be needed. > >>>> > >>>> I think the main point that Dmitry Torokhov conveys here is that we > >>>> should minimize the possible impact on the current EKT3500 code since we > >>>> don't have definitive answers regarding the firmware differences among > >>>> the hardware variants. > >>> > >>> The only possible impact here is that older firmware instead of breaking > >>> would suddenly work. Maybe we can accept such a risk? > >> > >> These are not controllers we'll randomly find in devices: Windows boxes > >> use I2C HID, Chrome devices use "new" firmware, so that leaves random > >> ARM where someone needs to consciously add proper compatible before the > >> driver will engage with the controller. > >> > >> I would prefer we were conservative and not accept potentially invalid > >> data. > >> > >> Thanks. > >> > > > > Michał, will you be able to make v9 with all the review comments addressed? > > > > I'll make a v9 over this weekend. > > Michał, please let me know if you already started to work on this or > have any objections. Hi, Sorry for staying quiet so long. I have to revive my Transformer before I can test anything, so please go ahead. Best Regards Michał Mirosław