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=-12.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 17E31C433DB for ; Mon, 11 Jan 2021 14:18:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D91522242A for ; Mon, 11 Jan 2021 14:18:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728553AbhAKOS6 (ORCPT ); Mon, 11 Jan 2021 09:18:58 -0500 Received: from mailout1.w1.samsung.com ([210.118.77.11]:55411 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726442AbhAKOS5 (ORCPT ); Mon, 11 Jan 2021 09:18:57 -0500 Received: from eucas1p1.samsung.com (unknown [182.198.249.206]) by mailout1.w1.samsung.com (KnoxPortal) with ESMTP id 20210111141815euoutp01f24f323226eca548c2fd6068079bf0e8~ZM0DNbMWR2032620326euoutp01D for ; Mon, 11 Jan 2021 14:18:15 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.w1.samsung.com 20210111141815euoutp01f24f323226eca548c2fd6068079bf0e8~ZM0DNbMWR2032620326euoutp01D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1610374695; bh=ZQDAz6BC3qKM7ZG/PUFs4ihPyhHWnAL2/UEgubN3WFs=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=VNCWSE9Vablquv3+mom8g0Z7et+fWuThUkilxlpeTqbP0W3mVja4a4QH9Jtqcd/Qo MEND70YYwIYmqP6uIXZs44u5T4Ea7qgu2asQCjKgF0oMVe2+X0j3tFOq0pkJLEYhCp e6dowsCtFhxpPDzORWOu5Kd2XwlkC3uuATK364FM= Received: from eusmges3new.samsung.com (unknown [203.254.199.245]) by eucas1p1.samsung.com (KnoxPortal) with ESMTP id 20210111141814eucas1p17c97b6fa6d68cda068046b1f8c2f95e2~ZM0C8HtMO2955429554eucas1p1p; Mon, 11 Jan 2021 14:18:14 +0000 (GMT) Received: from eucas1p2.samsung.com ( [182.198.249.207]) by eusmges3new.samsung.com (EUCPMTA) with SMTP id 5C.68.45488.62E5CFF5; Mon, 11 Jan 2021 14:18:14 +0000 (GMT) Received: from eusmtrp2.samsung.com (unknown [182.198.249.139]) by eucas1p1.samsung.com (KnoxPortal) with ESMTPA id 20210111141814eucas1p1f388df07b789693a999042b27f0d8c2a~ZM0Cd1PuD0148801488eucas1p1T; Mon, 11 Jan 2021 14:18:14 +0000 (GMT) Received: from eusmgms2.samsung.com (unknown [182.198.249.180]) by eusmtrp2.samsung.com (KnoxPortal) with ESMTP id 20210111141814eusmtrp27c7838094414c3858a92ee5f6eefb1da~ZM0CdCOUL0526205262eusmtrp2D; Mon, 11 Jan 2021 14:18:14 +0000 (GMT) X-AuditID: cbfec7f5-c5fff7000000b1b0-63-5ffc5e266600 Received: from eusmtip2.samsung.com ( [203.254.199.222]) by eusmgms2.samsung.com (EUCPMTA) with SMTP id 53.91.16282.62E5CFF5; Mon, 11 Jan 2021 14:18:14 +0000 (GMT) Received: from [106.210.134.192] (unknown [106.210.134.192]) by eusmtip2.samsung.com (KnoxPortal) with ESMTPA id 20210111141813eusmtip24ce6cb5a7e05b7a2ff62cf0d3df93374~ZM0BsEOtO0173401734eusmtip2l; Mon, 11 Jan 2021 14:18:13 +0000 (GMT) Subject: Re: [PATCH v1 5/5] driver core: Set fw_devlink=on by default From: Marek Szyprowski To: Saravana Kannan , Greg Kroah-Hartman , "Rafael J. Wysocki" Cc: kernel-team@android.com, linux-kernel@vger.kernel.org, Jisheng Zhang , Kevin Hilman , John Stultz , Nicolas Saenz Julienne , Marc Zyngier , 'Linux Samsung SOC' , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz Message-ID: <2556a69b-5da5-bf80-e051-df2d02fbc40f@samsung.com> Date: Mon, 11 Jan 2021 15:18:13 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <5484316b-0f27-6c36-9259-5c765bb6b96c@samsung.com> Content-Transfer-Encoding: 8bit Content-Language: en-US X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrAKsWRmVeSWpSXmKPExsWy7djP87pqcX/iDSbPMLTYOGM9q0Xz4vVs FtNuLmexOPNb12LHdhGLn+1bmCzOn9/AbnF51xw2ixnn9zFZ7JxzktVi26zlbBZzv0xltug6 9JfNgddj2+5trB7vb7SyeyzYVOqxaVUnm8eda3vYPPbPXcPu0bdlFaPH5tPVHpOunGP2+LxJ LoArissmJTUnsyy1SN8ugSuj6VofS8E/wYrTO24xNzA+4uti5OSQEDCRaF+3kK2LkYtDSGAF o8T7hTeYIJwvjBK/3rSwQjifGSXm7Z7JCNNyfvFRFojEckaJw02L2SGcj4wSHz6cBnI4OIQF XCW+HPcBaWATMJToetsFtkNEoI1R4uG+nywgCWaBhcwSE65kgdi8AnYSM1dsZQWxWQRUJdoO PWcCsUUFkiSO7+tmhqgRlDg58wlYL6eAvcTa4yeZIebISzRvnQ1li0vcejKfCeLS5ZwS02dL Q9guEuvbzzJD2MISr45vYYewZST+75wP9rOEQDPQcefWskM4PYwSl5tmQP1sLXHn3C82kM+Y BTQl1u/SBzElBBwlDr+qgDD5JG68FYQ4gU9i0rbpzBBhXomONiGIGWoSs46vg9t68MIl5gmM SrOQPDYLyTOzkDwzC2HtAkaWVYziqaXFuempxcZ5qeV6xYm5xaV56XrJ+bmbGIGJ7vS/4193 MK549VHvECMTB+MhRgkOZiUR3oW7fsQL8aYkVlalFuXHF5XmpBYfYpTmYFES5921dU28kEB6 YklqdmpqQWoRTJaJg1OqgSnR3qL0XMoS2UqT95HzEzw6FFYXnOvectX2oPzxP2Iic+T71dpq XzPcKND56nSgNXXKhwAWSfnIORMZe7NuXDgVxaf5onTWCzV/lgafBp4jJyTvLnRhWMTUkrey L/57717dYEOXk9mXw5pvekx+cvm2cXquSuze58ZP30v5utmuL1zDeFpk97lVB9Mlii8p7bET k+Ri8xaS4G4JEDkvc3qC/vuSt0eyPdj9J5y5pnN6hUYx/yLX5TkBJtPV6pe9mr2o5Grq4tTm 6Xu5Pa8/2Hthpdfy64kKd9bOnpBpd//KhO53fwXLt3M1aLCemp3hqH7p7aqfGX3iucq8Odv3 1EmIbczz0jgfceRU8beSdUosxRmJhlrMRcWJAMdT6tzjAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrCIsWRmVeSWpSXmKPExsVy+t/xe7pqcX/iDRq28FhsnLGe1aJ58Xo2 i2k3l7NYnPmta7Fju4jFz/YtTBbnz29gt7i8aw6bxYzz+5gsds45yWqxbdZyNou5X6YyW3Qd +svmwOuxbfc2Vo/3N1rZPRZsKvXYtKqTzePOtT1sHvvnrmH36NuyitFj8+lqj0lXzjF7fN4k F8AVpWdTlF9akqqQkV9cYqsUbWhhpGdoaaFnZGKpZ2hsHmtlZKqkb2eTkpqTWZZapG+XoJfR dK2PpeCfYMXpHbeYGxgf8XUxcnJICJhInF98lKWLkYtDSGApo8TVf7eYIRIyEienNbBC2MIS f651sUEUvWeUuH/7HlMXIweHsICrxJfjPiA1bAKGEl1vIWpEBDoYJb5dvQ7mMAssZZZYeOga M0T3IkaJh8vOs4C08ArYScxcsRVsBYuAqkTboedgU0UFkiQWv3WCKBGUODnzCVg5p4C9xNrj J8GuYxYwk5i3+SGULS/RvHU2lC0ucevJfKYJjEKzkLTPQtIyC0nLLCQtCxhZVjGKpJYW56bn FhvpFSfmFpfmpesl5+duYgRG97ZjP7fsYFz56qPeIUYmDsZDjBIczEoivAt3/YgX4k1JrKxK LcqPLyrNSS0+xGgK9M5EZinR5HxgeskriTc0MzA1NDGzNDC1NDNWEuc1ObImXkggPbEkNTs1 tSC1CKaPiYNTqoHJV9P44ZZ3PjzG86fLhF3uqI7laJOPntDHZGT+uVIopPRQv7SwZImgTdyr edO3zi1Vdt556znbMXeHlgUs2eJbblvItHnZX2aNi4p0DRNz+rMhbe6KMJflZ+wOK5de6bC4 vrKfj8s6vE7vk6rPZOXnp21XGMUr3bnEN+vBsw05/WpK34S2r2a+uLFrjtKPPRnnj/A/kHx3 q+nC5mvvWBasTLlopb87ZPdZPaNPh3sYlnzcsXFKd/jC/dZZl5pmr7Mr3jn9pkh/j+CxhphX Nzce3ZUg9qfF4OBP7+SmE2aW0mw+kxZP/qFdK5e9i8EhWnnmw+j4vTnl965sXx6QkXXkrIbQ RfOjoWpH9/38/rNfiaU4I9FQi7moOBEAIPhc7XcDAAA= X-CMS-MailID: 20210111141814eucas1p1f388df07b789693a999042b27f0d8c2a X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20210111141814eucas1p1f388df07b789693a999042b27f0d8c2a X-EPHeader: CA CMS-TYPE: 201P X-CMS-RootMailID: 20210111141814eucas1p1f388df07b789693a999042b27f0d8c2a References: <20201218031703.3053753-1-saravanak@google.com> <20201218031703.3053753-6-saravanak@google.com> <5484316b-0f27-6c36-9259-5c765bb6b96c@samsung.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11.01.2021 12:12, Marek Szyprowski wrote: > On 18.12.2020 04:17, Saravana Kannan wrote: >> Cyclic dependencies in some firmware was one of the last remaining >> reasons fw_devlink=on couldn't be set by default. Now that cyclic >> dependencies don't block probing, set fw_devlink=on by default. >> >> Setting fw_devlink=on by default brings a bunch of benefits (currently, >> only for systems with device tree firmware): >> * Significantly cuts down deferred probes. >> * Device probe is effectively attempted in graph order. >> * Makes it much easier to load drivers as modules without having to >>    worry about functional dependencies between modules (depmod is still >>    needed for symbol dependencies). >> >> If this patch prevents some devices from probing, it's very likely due >> to the system having one or more device drivers that "probe"/set up a >> device (DT node with compatible property) without creating a struct >> device for it.  If we hit such cases, the device drivers need to be >> fixed so that they populate struct devices and probe them like normal >> device drivers so that the driver core is aware of the devices and their >> status. See [1] for an example of such a case. >> >> [1] - >> https://lore.kernel.org/lkml/CAGETcx9PiX==mLxB9PO8Myyk6u2vhPVwTMsA5NkD-ywH5xhusw@mail.gmail.com/ >> Signed-off-by: Saravana Kannan > > This patch landed recently in linux next-20210111 as commit > e590474768f1 ("driver core: Set fw_devlink=on by default"). Sadly it > breaks Exynos IOMMU operation, what causes lots of devices being > deferred and not probed at all. I've briefly checked and noticed that > exynos_sysmmu_probe() is never called after this patch. This is really > strange for me, as the SYSMMU controllers on Exynos platform are > regular platform devices registered by the OF code. The driver code is > here: drivers/iommu/exynos-iommu.c, example dts: > arch/arm/boot/dts/exynos3250.dtsi (compatible = "samsung,exynos-sysmmu"). Okay, I found the source of this problem. It is caused by Exynos power domain driver, which is not platform driver yet. I will post a patch, which converts it to the platform driver. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland