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=-5.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 639A4C48BE5 for ; Wed, 16 Jun 2021 14:41:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42D8A60FE6 for ; Wed, 16 Jun 2021 14:41:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234119AbhFPOn5 (ORCPT ); Wed, 16 Jun 2021 10:43:57 -0400 Received: from mout.kundenserver.de ([212.227.126.130]:39925 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233914AbhFPOn5 (ORCPT ); Wed, 16 Jun 2021 10:43:57 -0400 Received: from [192.168.1.155] ([95.115.35.150]) by mrelayeu.kundenserver.de (mreue011 [212.227.15.167]) with ESMTPSA (Nemesis) id 1MSLEm-1licf82p6u-00SerU; Wed, 16 Jun 2021 16:41:26 +0200 Subject: Re: [PATCH] drivers: gpio: add virtio-gpio guest driver To: Linus Walleij , "Enrico Weigelt, metux IT consult" , Viresh Kumar Cc: linux-kernel , Jonathan Corbet , Bartosz Golaszewski , "Michael S. Tsirkin" , Jason Wang , Kees Cook , Anton Vorontsov , Colin Cross , Tony Luck , Linux Doc Mailing List , "open list:GPIO SUBSYSTEM" , virtualization@lists.linux-foundation.org, linux-riscv References: <20210615174911.973-1-info@metux.net> From: "Enrico Weigelt, metux IT consult" Message-ID: <098f669f-b451-18e1-9aed-a71f400bd581@metux.net> Date: Wed, 16 Jun 2021 16:41:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: tl Content-Transfer-Encoding: 8bit X-Provags-ID: V03:K1:CR6mpicfGsY9r/evUqTXH8C70befzHJD17gK1boMJb2mNiw2I3w u9bascsokR1YLBsRaAjFl9nCA0nXMUduSAIVdTJsuBt//Y1hu5AbrPkpQ5Bewzb1Peh7x0m OJsttVts/KwE3xipe3/w+Di4ulseb46HgCXAWsbZwtIW1CWD52UQu24Sh7tjYr+AujL6fle DtR3xtegpA75e0CGxI5aw== X-UI-Out-Filterresults: notjunk:1;V03:K0:fMVu1T4nu7g=:4lDZNogMmvE1wFbQcnZQ0B hBMiXVmcPPsYTquq0lJBIq7dqufr+FVBlwhCMtjMCtupVmGeVKmzhQLeZtIn0EqCtwP17PQC1 bI4PhWcGXUahcXYS6EV82U3W2kaSYt7WSXN334mB665gcj2/yg90+n9mZ+hGyJiwnS+1XcWQ/ U6OflJL9RiKDC/q+61jIjkRcm+8bbuwuCA4idwY9O67k50FabdiGYUKE1RmY05OjaAxgnk0AO jZBLFx00sKx0u7GOr3YKFhpHV84KJIdnhRy9FXO4LOE5OIgUnJDHC+FG2it+fuzaV5ud9zpzM Iztr85Sus6eg7hgkhxUxp+6GOYiOKJSNC1csHjDXN+RIw93lfgeqglRhXvzIDq7qAlKFORGbc SgnoSFASpckcaCipHWdnINRFf+zjpPLo55xzD0+rMIVAbabemAUPj8ZuOEqiYgaqgM/WGa2Hy /xsV6746LXXSuzAPiwPRjHVo4p2NJAqyjnjVbgO/gaw7BsyePIXVOSmAkD1jA7tBvxgXAny0C 6dcDS5dKyeTDANgMo4EGqI= Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On 16.06.21 10:31, Linus Walleij wrote: > Hi Enrico, > So now there are two contesting patches for this and that creates a > social problem for us as maintainers. I am not too happy about that. note that this is a polished up of a repost of my original driver from last year. > Can we get the discussion down to actual technical points? Sure. Perhaps you recall or discussions from late 2020. The missing point there was (besides a few wording issues) the missing formal specification process w/ virtio TC. (spec was already included in this driver as well as the corresponding qemu patches). My spec was not just meant for VM applications but also actual silicon (as already mentioned, some folks of my client also implemented it in FPGAs - don't ask me about details, they just mentioned it was quite easy for them). This is why it is so trimmed on things like fixed packet size, unidirectional queues, mirroring packets w/ thus a few bits changed, etc. In constrast, a more network-like approach might have been looking nicer to traditional computer programmers, but much more complex to do in pure logic and eat up *lots of* more gates (think of actual memory management instead of hardwired latches, more complex decoding, etc). Meanwhile it played out working nicely in several HIL installations If I wanted to have a simple and CPU-only approach (just for VMs), I would have just mounted some sysfs pieces via 9P :p Several weeks ago, Viresh just wanted to continue the missing pieces (which was: tex'ifying the spec and submitting to virtio TC), but then unfortunately he invented something entirely different also put my name on it. Easy to imagine that I'm not amused at all. --mtx -- --- Hinweis: unverschlüsselte E-Mails können leicht abgehört und manipuliert werden ! Für eine vertrauliche Kommunikation senden Sie bitte ihren GPG/PGP-Schlüssel zu. --- Enrico Weigelt, metux IT consult Free software and Linux embedded engineering info@metux.net -- +49-151-27565287 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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 69F81C48BE5 for ; Wed, 16 Jun 2021 14:42:14 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0E6316115C for ; Wed, 16 Jun 2021 14:42:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E6316115C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=metux.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:Cc:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=diQgurVrAKPXs6zBNlA2s9vqqv4DwXIPP6zsBwHaWQQ=; b=QeM5rCGtnCbSZk2fzIGlVq9pbK /enquPEYGypM4DtjdcVbIzUcQ4QtvUqJQfjtQ08/iike1tZe1yT8Qv4KYoJCidHeOtpxX6E9uWuGf 54gwm2vAP2iBqBJtFM3w75zV1V39kHxU6/TBwRjO24Ct6mcXfS2pScYhnZs2dc9tUsYg6jFi4hz6C pmxt8Jq3rnznjZjttoR0OfXccL7WRWwUb+vuFeO0A0fpT3hT2HIJW0oSmnxxTNA6cpH4a2O4+CQes OG34vphC+qHOVD54ycyxG3KZU6qziaCVUFutnlesw59S5slyvlXIbLY9eUqtf1Hr9tr9B9hSK8NED zIXSj42g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ltWjm-006knS-DA; Wed, 16 Jun 2021 14:41:50 +0000 Received: from mout.kundenserver.de ([212.227.126.130]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ltWjj-006kmz-9u for linux-riscv@lists.infradead.org; Wed, 16 Jun 2021 14:41:48 +0000 Received: from [192.168.1.155] ([95.115.35.150]) by mrelayeu.kundenserver.de (mreue011 [212.227.15.167]) with ESMTPSA (Nemesis) id 1MSLEm-1licf82p6u-00SerU; Wed, 16 Jun 2021 16:41:26 +0200 Subject: Re: [PATCH] drivers: gpio: add virtio-gpio guest driver To: Linus Walleij , "Enrico Weigelt, metux IT consult" , Viresh Kumar Cc: linux-kernel , Jonathan Corbet , Bartosz Golaszewski , "Michael S. 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