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=-9.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 5478AC433EA for ; Tue, 21 Jul 2020 15:04:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3360B20709 for ; Tue, 21 Jul 2020 15:04:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YK4OMZ0X" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728385AbgGUPEv (ORCPT ); Tue, 21 Jul 2020 11:04:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726436AbgGUPEt (ORCPT ); Tue, 21 Jul 2020 11:04:49 -0400 Received: from mail-ej1-x644.google.com (mail-ej1-x644.google.com [IPv6:2a00:1450:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0ADC6C061794; Tue, 21 Jul 2020 08:04:49 -0700 (PDT) Received: by mail-ej1-x644.google.com with SMTP id o18so21956732eje.7; Tue, 21 Jul 2020 08:04:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=x/WjG1I1jw+gA2WhVK85qv6i+E0OUDyTrccx3Mlc7NQ=; b=YK4OMZ0XyyX1/+bnU5uyRqXAPi/NwezYZaL+3SQ/21qjHrQvQLB5QpTBCGqvSpfp2G 0dvwYRP2ggj8iJi1OFLEc31LD/505o64O72+/gTxoOZo76Ndlm3mGjn2EZv/v3G6+v4a aKSmHBy1odMqQ7JRmYtoXEwS7f1gQ80r15lfBdhYEhTjVZMovK7UqEUBiH2Q2fqM/ocX +MXyHN/tmxYATerUHB9o6fDhGL+9FS/qmTCpWlTNbDwE0ediAtl2ZW9ncZW7nHeQSIGm A9fkEK5kJth3K/5fZzZK8QDZ7eH9+cZYIb2athqhWpi5JDknWKM5MevSvPLujUL5Ns9o VsCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=x/WjG1I1jw+gA2WhVK85qv6i+E0OUDyTrccx3Mlc7NQ=; b=rQDJaDcW6td24SDb7pRMbc1NIQTx/OD5issXVX2IO0SC2fJHKRAptLg9GElRC+6+0F MgGZ8aEflJHK8JU7YoXwOuOEQ8/o+pn6OlhWCzYNGfY7jacKsA0/amq/6p39Y1u3sQG1 +P4hlryh/beHyJT3Fw2Lvii1aEFTmF3S6g6sF4zAKGRV6giy1g21IvCLIFFs2z1cF9wE wGzwVJ4lDP8h/m1ojkymcpRnfkplyCxMxk0v6+UEKKFGPsBYA5V2f/289K5Ny7hKVkPb NSswCtqaH3uGSDl8mk2A0IBKzgPeI4Pz0Xc0pWmLLhwpVhVIUy2LKlJu4Z5ANnM58zDJ /DMw== X-Gm-Message-State: AOAM530W9Gel86/iZKD3X/T63t+BbLC4Kv1RY4eB3Mkvuf5NiF6GkX2I E1BGVCvPzIkVwMMag3TOHoBcjmrLJ0QKOfcKIDo= X-Google-Smtp-Source: ABdhPJyUPjX5E5t4LX3TbhkOYN5/ZjIzw5tH08WLxfBJzEMURod+CD9+rMNIPF5jUFqS644hvbpGtTtu+Lo5lbvFQ98= X-Received: by 2002:a17:906:40cb:: with SMTP id a11mr24668088ejk.340.1595343887718; Tue, 21 Jul 2020 08:04:47 -0700 (PDT) MIME-Version: 1.0 References: <20200704122809.73794-1-konradybcio@gmail.com> <20200704130922.GB21333@willie-the-truck> <20200705033511.GR388985@builder.lan> In-Reply-To: <20200705033511.GR388985@builder.lan> From: Konrad Dybcio Date: Tue, 21 Jul 2020 17:04:11 +0200 Message-ID: Subject: Re: [PATCH 1/1] iommu/arm-smmu: Implement qcom,skip-init To: Bjorn Andersson Cc: Will Deacon , skrzynka@konradybcio.pl, Robin Murphy , Joerg Roedel , Rob Herring , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, DTML , Linux Kernel Mailing List , jcrouse@codeaurora.org, John Stultz Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org So.. is this a no-no? I of course would like to omit this entirely, but SMMUs on sdm630 and friends are REALLY picky.. What seems to happen is that when the driver tries to do things the "standard" way, hypervisor decides to hang the platform or force a reboot. Not very usable. This thing is needed for the platform to even boot properly and one more [1] is required to make mdss work with video mode panels (the fact that CMD-mode panels work is kinda hilarious to me). To be honest, there are even more qcom quirks (of which at least qcom,dynamic and qcom-use-3-lvl-tables are used on 630).. [2] Looking forward to your answers and possibly better solutions. [1] https://github.com/konradybcio/linux/commit/83ac38af259968f92b6a8b7eab90096c78469f87 [2] https://github.com/sonyxperiadev/kernel/blob/aosp/LA.UM.7.1.r1/drivers/iommu/arm-smmu.c#L404-L415 Regards Konrad