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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 42550C48BD4 for ; Tue, 25 Jun 2019 14:20:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1214C208E3 for ; Tue, 25 Jun 2019 14:20:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="PiKb0pq4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729965AbfFYOUg (ORCPT ); Tue, 25 Jun 2019 10:20:36 -0400 Received: from mail-ed1-f65.google.com ([209.85.208.65]:34210 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727738AbfFYOUg (ORCPT ); Tue, 25 Jun 2019 10:20:36 -0400 Received: by mail-ed1-f65.google.com with SMTP id s49so27463570edb.1 for ; Tue, 25 Jun 2019 07:20:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=sender:date:from:to:cc:subject:message-id:mail-followup-to :references:mime-version:content-disposition:in-reply-to:user-agent; bh=G6JtZL8+U2ZkwL0/tzXXiHIEAOss9zM+ZL3Pgbc8Mpk=; b=PiKb0pq4SASNR7D3rZRPPn6hYPGCPxODqKLMDAnrrKgPg9InzXFNxhgfcjJ0osnNob vyTtVKNuYim6MRswZ9WjaRBlsW8RMJPiwWKoyq3uAyYbDouZ9ZJClJkEADyVHPrEnO5E 2dv49ZPpK3sQqXzRaWmoTu0NM4VYZANoTUsRE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to:user-agent; bh=G6JtZL8+U2ZkwL0/tzXXiHIEAOss9zM+ZL3Pgbc8Mpk=; b=sOtLslIlVcnKC5o/DCC+axGvFhBBh6nZwyIE3DG8KmHMqOB87RqQf0jhrcVaTZFWsx 1arOirM/GpSS/4quWEAo62LIlpQLV3gFmKLimXq5q+dRzMhK1glQKOcpx8fHY2GbSQEZ P5SBRknKzBqpg3GeMbtRkNYsCssZU4f2IZzIuZ+T1FXDIE5e6SvbZVEhugToi5evLXwA rKr3cezdy8MkGCDIPNNJJDFvEfRM1/Pwh52p5HmBjWC+MPr4XC7ckFb2bOuxecSbOLnb D9jQh1dpXk0Ca7ujqc6Hun43eU3muADv9iFymnQG5XnI29E/xjtEPR45ETtHy6yQ407z 5F1A== X-Gm-Message-State: APjAAAVNY9451vlunRErhQco2V+ewg8LFZB1O+ipdtz3aa5XJVTe7sz8 geVUCsJNNRJ9RlssEaUzwfrfkw== X-Google-Smtp-Source: APXvYqzf+qJgnUeqQvG0q196yIL7BFlfF2ImhuXnDKq2Nc9RZ6ZHCnGm/JBXEdesWWdkz8OViVV3qw== X-Received: by 2002:a05:6402:78c:: with SMTP id d12mr111470360edy.160.1561472434802; Tue, 25 Jun 2019 07:20:34 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:569e:0:3106:d637:d723:e855]) by smtp.gmail.com with ESMTPSA id n15sm4863868edd.49.2019.06.25.07.20.33 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 25 Jun 2019 07:20:33 -0700 (PDT) Date: Tue, 25 Jun 2019 16:20:31 +0200 From: Daniel Vetter To: Russell King - ARM Linux admin Cc: Daniel Vetter , Emil Velikov , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, Joonyoung Shim , Maxime Ripard , Maarten Lankhorst , Seung-Woo Kim , Krzysztof Kozlowski , Andrzej Pietrasiewicz , Inki Dae , David Airlie , Kyungmin Park , Kukjin Kim , dri-devel@lists.freedesktop.org, kernel@collabora.com, Sean Paul , linux-kernel@vger.kernel.org, m.szyprowski@samsung.com Subject: Re: [PATCH 0/2] Associate ddc adapters with connectors Message-ID: <20190625142031.GV12905@phenom.ffwll.local> Mail-Followup-To: Russell King - ARM Linux admin , Emil Velikov , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, Joonyoung Shim , Maxime Ripard , Maarten Lankhorst , Seung-Woo Kim , Krzysztof Kozlowski , Andrzej Pietrasiewicz , Inki Dae , David Airlie , Kyungmin Park , Kukjin Kim , dri-devel@lists.freedesktop.org, kernel@collabora.com, Sean Paul , linux-kernel@vger.kernel.org, m.szyprowski@samsung.com References: <20190625100351.52ddptvb2gizaepi@shell.armlinux.org.uk> <817ccfba-754c-6a28-8d75-63f70605fd43@collabora.com> <20190625133639.GA16031@arch-x1c3> <20190625140755.GT12905@phenom.ffwll.local> <20190625141032.5jiy2oekb3olaejd@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190625141032.5jiy2oekb3olaejd@shell.armlinux.org.uk> X-Operating-System: Linux phenom 4.19.0-5-amd64 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 Tue, Jun 25, 2019 at 03:10:32PM +0100, Russell King - ARM Linux admin wrote: > On Tue, Jun 25, 2019 at 04:07:55PM +0200, Daniel Vetter wrote: > > Otherwise I like this. Biggest problem I'm seeing here is rolling this out > > everywhere, this is a lot of work. And without widespread adoptions it's > > not terribly useful for userspace. > > There will be cases where it's not possible, because the I2C bus is > hidden behind a chip that doesn't give you direct access to the DDC > bus. Oh sure, plus lots of connectors where there's just not ddc bus at all. But if we only roll this out for a handful of drivers it's also not great, that's what I meant. Looking at $ git grep drm_do_get_edid there's only very few drivers where the ddc bus is hidden. There's a lot more where it's not, and I think a big series to tackle those would serve extremely well to make a case for this sysfs link. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch