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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90475C433F5 for ; Wed, 29 Sep 2021 21:27:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A952613A6 for ; Wed, 29 Sep 2021 21:27:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347040AbhI2V3T (ORCPT ); Wed, 29 Sep 2021 17:29:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346978AbhI2V3O (ORCPT ); Wed, 29 Sep 2021 17:29:14 -0400 Received: from mail-lf1-x12a.google.com (mail-lf1-x12a.google.com [IPv6:2a00:1450:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 260C3C061770 for ; Wed, 29 Sep 2021 14:27:33 -0700 (PDT) Received: by mail-lf1-x12a.google.com with SMTP id j5so11559345lfg.8 for ; Wed, 29 Sep 2021 14:27:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=vjQP0/+z55MvzkQLmpO17f1ojfgarxRQxkpypeDCRYQ=; b=P6d7v/ARFy2oAzNGlzkCFMmhuF0dw1E4Ty8/aKGGomT30aic5OSINMht/5eTnTjw+E HVwG/Vb0f044xHEAedWSzxWElToMUBbgbJq2HpAC0E3cTqgTRqpyyvO/TxZlRGm7Knzd g197vNwd2IHxhZjeaz4yRtAoxCOvziEh/yVbtU+3O8VuswsBr07x1VFM5xAtgWihuCkO uaX1aUCJfdL12bZY+cJm7vPnn7R7kAZO2pzg6uXgoaCGHwkzYiXL2tUrJgQgg6Kyykb/ RcZANF9j+IZ5JhNrzRCHZVii00VULrEZwGuwD9dkVZiGUnoOdzpJdvJXgmdVANl52dPG GeTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=vjQP0/+z55MvzkQLmpO17f1ojfgarxRQxkpypeDCRYQ=; b=K/7/p6RVgT6q6SNePe8rK3URGHv6ldYCHsskk3r+J6IVFpMyxrEaYHrXT1rCnKYsFM 6EPaSD8J3zE0y8a0LcOzUSwaVpdIQUz0Q5AyZAOEXO+tXM/Y+XDeNqcwTiHPtI59sF+r q8uvhmFk2tT6UmDB7ynifgHiqWe4t8HwPjRXBDL7JDwsbEvFL/CTY1poALmw66JANFzD ksKtNhXX26tlKxHxz1Ugf7/TVDN4c94OYNQT6pIV8bpltUM5Ifi3vIK4KBsODMeDKVns 9KhZj+3DuNpoEtzOn7UlwfhoqB0INZRq2rAvPR7jmQjcw+cr319aa6UZkT4fIgGNphGG e+1A== X-Gm-Message-State: AOAM532jPTAFVxZXhj6tkpTar8T0qRimYNJonyhDXR8djCDoEDD9DqW9 0jUc2hmtj9/UuRAMY1p8QX4Arp5nkHu4llLRK0pd2Q== X-Google-Smtp-Source: ABdhPJxlRl2WWh8eZDcWokrINznDZYEeyO4HbV5UfIxRhCovDEAxjUhr3yg0Uy13hYjMGKtihX9SR8gKl3bzVxFYltc= X-Received: by 2002:a05:6512:ea5:: with SMTP id bi37mr1986548lfb.36.1632950851440; Wed, 29 Sep 2021 14:27:31 -0700 (PDT) MIME-Version: 1.0 References: <20210910101218.1632297-1-maxime@cerno.tech> In-Reply-To: <20210910101218.1632297-1-maxime@cerno.tech> From: John Stultz Date: Wed, 29 Sep 2021 14:27:19 -0700 Message-ID: Subject: Re: [PATCH v4 00/24] drm/bridge: Make panel and bridge probe order consistent To: Maxime Ripard Cc: Andrzej Hajda , Sam Ravnborg , Daniel Vetter , David Airlie , Jonas Karlman , Laurent Pinchart , Thierry Reding , Maarten Lankhorst , Thomas Zimmermann , Neil Armstrong , Robert Foss , Jernej Skrabec , Sean Paul , "open list:DRM DRIVER FOR MSM ADRENO GPU" , Kyungmin Park , lkml , Xinliang Liu , Seung-Woo Kim , Tian Tao , Inki Dae , Linux Samsung SOC , linux-arm-msm , Rob Clark , dri-devel , Chen Feng , Xinwei Kong , Joonyoung Shim Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org On Fri, Sep 10, 2021 at 3:12 AM Maxime Ripard wrote: > > We've encountered an issue with the RaspberryPi DSI panel that prevented the > whole display driver from probing. > > The issue is described in detail in the commit 7213246a803f ("drm/vc4: dsi: > Only register our component once a DSI device is attached"), but the basic idea > is that since the panel is probed through i2c, there's no synchronization > between its probe and the registration of the MIPI-DSI host it's attached to. > > We initially moved the component framework registration to the MIPI-DSI Host > attach hook to make sure we register our component only when we have a DSI > device attached to our MIPI-DSI host, and then use lookup our DSI device in our > bind hook. > > However, all the DSI bridges controlled through i2c are only registering their > associated DSI device in their bridge attach hook, meaning with our change > above, we never got that far, and therefore ended up in the same situation than > the one we were trying to fix for panels. > > The best practice to avoid those issues is to register its functions only after > all its dependencies are live. We also shouldn't wait any longer than we should > to play nice with the other components that are waiting for us, so in our case > that would mean moving the DSI device registration to the bridge probe. > > I also had a look at all the DSI hosts, and it seems that exynos, kirin and msm > would be affected by this and wouldn't probe anymore after those changes. > Exynos and kirin seems to be simple enough for a mechanical change (that still > requires to be tested), but the changes in msm seemed to be far more important > and I wasn't confortable doing them. Hey Maxime, Sorry for taking so long to get to this, but now that plumbers is over I've had a chance to check it out on kirin Rob Clark pointed me to his branch with some fixups here: https://gitlab.freedesktop.org/robclark/msm/-/commits/for-mripard/bridge-rework But trying to boot hikey with that, I see the following loop indefinitely: [ 4.632132] adv7511 2-0039: supply avdd not found, using dummy regulator [ 4.638961] adv7511 2-0039: supply dvdd not found, using dummy regulator [ 4.645741] adv7511 2-0039: supply pvdd not found, using dummy regulator [ 4.652483] adv7511 2-0039: supply a2vdd not found, using dummy regulator [ 4.659342] adv7511 2-0039: supply v3p3 not found, using dummy regulator [ 4.666086] adv7511 2-0039: supply v1p2 not found, using dummy regulator [ 4.681898] adv7511 2-0039: failed to find dsi host [ 4.688836] adv7511 2-0039: supply avdd not found, using dummy regulator [ 4.695724] adv7511 2-0039: supply dvdd not found, using dummy regulator [ 4.702583] adv7511 2-0039: supply pvdd not found, using dummy regulator [ 4.709369] adv7511 2-0039: supply a2vdd not found, using dummy regulator [ 4.716232] adv7511 2-0039: supply v3p3 not found, using dummy regulator [ 4.722972] adv7511 2-0039: supply v1p2 not found, using dummy regulator [ 4.738720] adv7511 2-0039: failed to find dsi host I'll have to dig a bit to figure out what's going wrong, but wanted to give you the heads up that there seems to be a problem thanks -john