Received: by 2002:a05:7412:b795:b0:e2:908c:2ebd with SMTP id iv21csp422870rdb; Thu, 2 Nov 2023 07:34:20 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFvaitc2BQ8vujizlp5lXg8YTzQgImtfBwiKkWwYSiNZDKF2ZYhxPMji7j9rJPsWOZlx6jS X-Received: by 2002:a05:6a20:428a:b0:16b:cc6c:d728 with SMTP id o10-20020a056a20428a00b0016bcc6cd728mr19967214pzj.44.1698935660471; Thu, 02 Nov 2023 07:34:20 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1698935660; cv=none; d=google.com; s=arc-20160816; b=EjPkIHK44//I6ZR4fCKRLmbK/EETwXKRDGXrCA93BeSjEK3WGUA9Nyib1ZxjtBYPhX V4kuBT8r3xMtj7Z6bmVFA06vzhrUjNs/bDUs3tBnPNZ4QoH0V/8kKzhNJ/iTI7VfnzFY otmHL541k4mp+6K47Pcj1s6vVgVGFQkwipi9edc/S9DlAc1OY3NDxpkwn3+GjAsuJTu9 O6rFcNn7jtv7HAM7LXJfp3n7RCYxwT4ysjFXQKa8vZu4/Q7GeKwHg5rN7N5YbBF5ihLV 6Jbjja3aU+Ofb9X4VbzkG4gxBCL8XCSMYcmZE/BNzjxXY1VzgDFEWxv4eSp01IsZFCoP NY1w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:cc:to:subject :message-id:date:from:in-reply-to:references:mime-version :dkim-signature; bh=cgks7+Mrd9UjN3I3/bxrqGWTtSqcTUrWZCfSRhD5piA=; fh=z9E5X1KSeR4cDvJhp4OSYe0SuSxgigagntge2R0EWGo=; b=H5+ohVtUPlgs1zsAFS80yPvdRZcIvNn6Uud9HmDFaaM8wHRkPfd/L/BPH3fPphfHnL UR4RVI3IQ0PLzlzPQfUirQWPDx2z7BzCFNNc9RcdM83UpjtazAEIjwWstaXLConx2Jp4 8EnCAXLWIrtOfTBt37wIeS9YDp/0pbh6zxtyVg3K8CUCbu0dtdMM/5/tCbHH3dS81f31 3ux0FCoidd17E3N5wOB1ydk7fRxw6uklZwybxjKRU8Q7066mKbrVUzz7Ij4suS61CMQ5 xfIY94NLqS2risfvPp8Q5vHMrzbNzHZJ48W+zAE30+0FIWD37XJW9W0lwlJl2vkPPUsp dIsg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=TzTyRA8J; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Return-Path: Received: from snail.vger.email (snail.vger.email. [23.128.96.37]) by mx.google.com with ESMTPS id q16-20020a056a00085000b0068beee4922csi3886138pfk.23.2023.11.02.07.34.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Nov 2023 07:34:20 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37; Authentication-Results: mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=TzTyRA8J; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by snail.vger.email (Postfix) with ESMTP id A5D4D8230CED; Thu, 2 Nov 2023 07:34:17 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at snail.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229593AbjKBOeR (ORCPT + 99 others); Thu, 2 Nov 2023 10:34:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229549AbjKBOeP (ORCPT ); Thu, 2 Nov 2023 10:34:15 -0400 Received: from mail-ej1-x62f.google.com (mail-ej1-x62f.google.com [IPv6:2a00:1450:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB013187 for ; Thu, 2 Nov 2023 07:34:08 -0700 (PDT) Received: by mail-ej1-x62f.google.com with SMTP id a640c23a62f3a-99de884ad25so163403366b.3 for ; Thu, 02 Nov 2023 07:34:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1698935646; x=1699540446; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=cgks7+Mrd9UjN3I3/bxrqGWTtSqcTUrWZCfSRhD5piA=; b=TzTyRA8J1+iC8+eacsN1uxeMm/8nInr5DvvAnvdj75RFOGCLg5rNGBrWBNW30ihFu1 K0EZJrm1eV824GQ9wsD1x9zwy97FJv35zYT17Qld3e55v4reMLMCqFCOsJIcHpN7i4ke Zq92Bt0SxRgdDAaDrWPdoFmb6Hme6FQsviXg4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698935647; x=1699540447; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=cgks7+Mrd9UjN3I3/bxrqGWTtSqcTUrWZCfSRhD5piA=; b=FA9uQ1/TB23LS6owHrrLeSXN1u9AyqrKYOZDTqcaDQWLplBGoRHM6SFT5tUQQ4XXdI iGh0V154ioAoXePakVbAsQhDQxq1Z3THWimEBMCit3AvZpt5pGoeb8aeL6kHb5HcwHyV mbskNffj1KU6i4BKrTx+dAooMWv5+HBvLA8LaPsBRoNQSlkCBWKvEE2XaZuJdEKA/ONt q/Gn3QS8kKO5Tg4K57QPmy/dYdueN47Mf9mzoPH42iFt8mi+kt1LCMkVikVBPjSYIJnK YR1U6EU/MOyZzc6poQkhhdu0PsT2AfNv0nejBvqDaaBvu1IYKfDtlHQEOcr/zs4r4uRR ZaOQ== X-Gm-Message-State: AOJu0Yz3Zo+XwVUIWHhiTTp1TpFMNr24V5jKbDdX2SrxNsIvjendvXEp lArO9x8dRIt2KfOoUouBz3F27Yusr+O11f1bCCnFxw== X-Received: by 2002:a17:906:52d7:b0:9bf:7bef:fc08 with SMTP id w23-20020a17090652d700b009bf7beffc08mr3502873ejn.56.1698935646566; Thu, 02 Nov 2023 07:34:06 -0700 (PDT) Received: from mail-wm1-f47.google.com (mail-wm1-f47.google.com. [209.85.128.47]) by smtp.gmail.com with ESMTPSA id t25-20020a508d59000000b00532eba07773sm2429373edt.25.2023.11.02.07.34.05 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 02 Nov 2023 07:34:05 -0700 (PDT) Received: by mail-wm1-f47.google.com with SMTP id 5b1f17b1804b1-4078fe6a063so52575e9.1 for ; Thu, 02 Nov 2023 07:34:05 -0700 (PDT) X-Received: by 2002:a7b:c385:0:b0:400:c6de:6a20 with SMTP id s5-20020a7bc385000000b00400c6de6a20mr52452wmj.3.1698935645509; Thu, 02 Nov 2023 07:34:05 -0700 (PDT) MIME-Version: 1.0 References: <20231101212604.1636517-1-hsinyi@chromium.org> <20231101212604.1636517-4-hsinyi@chromium.org> In-Reply-To: From: Doug Anderson Date: Thu, 2 Nov 2023 07:33:48 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 3/3] drm/panel-edp: Choose correct preferred mode To: Dmitry Baryshkov Cc: Hsin-Yi Wang , Neil Armstrong , linux-kernel@vger.kernel.org, Maxime Ripard , dri-devel@lists.freedesktop.org, Thomas Zimmermann , Jessica Zhang , Sam Ravnborg Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (snail.vger.email [0.0.0.0]); Thu, 02 Nov 2023 07:34:17 -0700 (PDT) Hi, On Wed, Nov 1, 2023 at 11:31=E2=80=AFPM Dmitry Baryshkov wrote: > > On Wed, 1 Nov 2023 at 23:26, Hsin-Yi Wang wrote: > > > > If a non generic edp-panel is under aux-bus, the mode read from edid wo= uld > > still be selected as preferred and results in multiple preferred modes, > > which is ambiguous. > > > > If a hard-coded mode is present, unset the preferred bit of the modes r= ead > > from edid. > > Can we skip the EDID completely if the hardcoded override is present? Yeah, I wondered about that too. The blending of the hardcoded with the EDID predates my involvement with the driver. You can see even as of commit 280921de7241 ("drm/panel: Add simple panel support") that the driver would start with the EDID modes (if it had them) and then go onto add the hardcoded modes. At least for eDP panels, though, nobody (or almost nobody?) actually provided panel-simple a DDC bus at the same time it was given a hardcoded panel. I guess I could go either way, but I have a slight bias to adding the extra modes and just making it clear to userspace that none of them are "preferred". That seems like it would give userspace the most flexibility and also is closer to what we've historically done (though, historically, we just allowed there to be more than one "preferred" mode). One thing we definitely want to do, though, is to still expose the EDID to userspace even if we're using a hardcoded mode. I believe that, at least on ChromeOS, there are some tools that look at the EDID directly for some reason or another. > > Signed-off-by: Hsin-Yi Wang > > --- > > drivers/gpu/drm/drm_modes.c | 16 ++++++++++++++++ > > drivers/gpu/drm/panel/panel-edp.c | 7 +++++-- > > include/drm/drm_modes.h | 1 + > > 3 files changed, 22 insertions(+), 2 deletions(-) > > Anyway, this should be split into two patches. One for drm_modes.c, > another one for the panel driver. Yeah, that's probably a good idea. -Doug