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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E90A2C7EE2C for ; Mon, 29 May 2023 16:28:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229573AbjE2Q23 (ORCPT ); Mon, 29 May 2023 12:28:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229502AbjE2Q21 (ORCPT ); Mon, 29 May 2023 12:28:27 -0400 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93E64AB; Mon, 29 May 2023 09:28:25 -0700 (PDT) Received: by mail-wm1-x331.google.com with SMTP id 5b1f17b1804b1-3f6da07ff00so36298435e9.3; Mon, 29 May 2023 09:28:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1685377704; x=1687969704; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=2iKyeVxpYOPIGYe/Lxm4HI6qu/yiKmBXO8zVnrWLpCU=; b=EpgmH9C6n5uyhLbAytYKg1lA2SVWmxLhgqXm1xmhHfyRF0cp7zejDIcXKiCOd/EkHc lJIpPh7f+lCohgmAvAACNj6NtHaPhXMHKg9a/1/VIYzTiRhn6x2LWHZJi68XifC3mRJI M3Z4b4rjMXd+jU9mNWH6+Q9me/xHAkVmLSql84N+hYQDlhrXNMp5t/3z6xDJly6Vv+Xb +VVlAxN3nrAj3MkDBuSILGgXIKAVFZ5TnPECDlY3JGBc/ph6RWAStiyGZMvTDLIgVWBO nbOejSBvsD/+OMxkRwRl19Bgf7Rsp3Y7zuinC3hX3Q9e+cVV9V0Np7Q/ycx4MsnnzGgA +Mug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685377704; x=1687969704; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=2iKyeVxpYOPIGYe/Lxm4HI6qu/yiKmBXO8zVnrWLpCU=; b=XK2DaFOk9/fwmizwmYwJQd/g5MQR2475JRRbAb3ZJSCZqYB2ZcNPVmJ7p6zXWeP99G y2eG/4kaq4RFt5eZAV09sQuzT35AievbArTGsOplPPqsqMIwB14pzsvjgaUMZdx9XloG 5CKNf6qBlie/qWxDZ0RBaZtyBREltsjhLcIxkhksMv5aOimrAzkaQO4gFZAbIlTBWj6o h73D4hPSCKQ7sb2rF5oJK3fn5iYVdj9JAa1cKxcvG43R6rpFqKScqDAgop0oIxyODJ6D iKR/laGbUrYJLSiV+EHL9RTqzcv79eBJbwJh/ItxPZag25VbiukUcLi/dnXl/uQlMu02 N/fg== X-Gm-Message-State: AC+VfDxQXnA4jI+VlIkHZzZiJMwEzKIH0Ef2E0bQhoj84j9auNNMLpHu xUXEj3klMwGbVLb15r3Xg3A= X-Google-Smtp-Source: ACHHUZ4nt4/ZUaLSDt/sbuRs0jUlCrpJSZ4JbtG0UP+yrn/Tqv+Tk0qeFK4rvij2BzsefX+Pdi2pHg== X-Received: by 2002:a1c:4c04:0:b0:3f6:962d:405c with SMTP id z4-20020a1c4c04000000b003f6962d405cmr8550475wmf.41.1685377703937; Mon, 29 May 2023 09:28:23 -0700 (PDT) Received: from [192.168.2.177] ([207.188.167.132]) by smtp.gmail.com with ESMTPSA id k5-20020a7bc405000000b003f31cb7a203sm14715125wmi.14.2023.05.29.09.28.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 29 May 2023 09:28:22 -0700 (PDT) Message-ID: <3069dcf7-28e0-e7f6-11d5-9bc286d7d6e3@gmail.com> Date: Mon, 29 May 2023 18:28:21 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH] arm64: dts: mediatek: mt8173-elm: remove panel model number in DT Content-Language: en-US, ca-ES, es-ES To: Icenowy Zheng , AngeloGioacchino Del Regno , Doug Anderson , Pin-yen Lin Cc: Rob Herring , Krzysztof Kozlowski , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, dri-devel@lists.freedesktop.org References: <20230526100801.16310-1-uwu@icenowy.me> <6996788b112f4795d2930a6664b3152cd9a380a8.camel@icenowy.me> From: Matthias Brugger In-Reply-To: <6996788b112f4795d2930a6664b3152cd9a380a8.camel@icenowy.me> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29/05/2023 10:45, Icenowy Zheng wrote: > 在 2023-05-29星期一的 10:02 +0200，AngeloGioacchino Del Regno写道： >> Il 26/05/23 16:24, Doug Anderson ha scritto: >>> Hi, >>> >>> On Fri, May 26, 2023 at 3:09 AM Icenowy Zheng >>> wrote: >>>> >>>> Currently a specific panel number is used in the Elm DTSI, which >>>> is >>>> corresponded to a 12" panel. However, according to the official >>>> Chrome >>>> OS devices document, Elm refers to Acer Chromebook R13, which, as >>>> the >>>> name specifies, uses a 13.3" panel, which comes with EDID >>>> information. >>>> >>>> As the kernel currently prioritizes the hardcoded timing >>>> parameters >>>> matched with the panel number compatible, a wrong timing will be >>>> applied >>>> to the 13.3" panel on Acer Chromebook R13, which leads to blank >>>> display. >>>> >>>> Because the Elm DTSI is shared with Hana board, and Hana >>>> corresponds to >>>> multiple devices from 11" to 14", a certain panel model number >>>> shouldn't >>>> be present, and driving the panel according to its EDID >>>> information is >>>> necessary. >>>> >>>> Signed-off-by: Icenowy Zheng >>>> --- >>>>   arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 2 +- >>>>   1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> We went through a bunch of back-and-forth here but in the end in >>> the >>> ChromeOS tree we have "edp-panel" as the "compatible" here in the >>> ChromeOS 5.15 tree and this makes sense. >>> >>> Reviewed-by: Douglas Anderson >>> >>> ...in theory one would wish for a "Fixes" tag, but I think in >>> previous >>> discussions it was decided that it was too complicated. Hardcoding >>> the >>> other compatible string has always been technically wrong, but I >>> guess >>> it worked at some point in time. The more correct way (as you're >>> doing >>> here) needs the DP AUX bus support and the generic eDP panels, both >>> of >>> which are significantly newer than the elm dts. So I guess leaving >>> no >>> "Fixes" tag is OK, or perhaps you could do the somewhat weak: >>> >>> Fixes: c2d94f72140a ("arm64: dts: mediatek: mt8173-elm: Move >>> display >>> to ps8640 auxiliary bus") >> >> I remember I didn't change the compatible to panel-edp because it >> didn't >> work at that time, but it does now... I'm not sure what actually >> fixed that >> and if the commit(s) was/were backported to that suggested point, so >> I >> would leave the Fixes tag out, as that may break older kernel. > > Well at least I developed this patch on v6.3. > > (In fact the same kernel config do not boot to system at all on > v6.0/v6.1 when I do make olddefconfig then build) > I applied the patch without the fixes tag. Lets stay on the secure side to not break older kernels. Regards, Matthias >> >> Anyway, for this commit: >> >> Reviewed-by: AngeloGioacchino Del Regno >> >