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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 F064AC433E1 for ; Sat, 15 Aug 2020 23:22:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9BC8206C0 for ; Sat, 15 Aug 2020 23:22:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597533752; bh=SB9wxVHgt3m7T/tEhx/Oa+YJt9VN49b1ddeU7NMOvEk=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=tL6iryON5tNZ+KX1KluD4jcVbTorWsjIFD5XKhl5dtUI2X1HlXz8LCImqwwFSGN4L 4Ih6V8axb89aC5UTVFRnBLhciBBHu15M9xUV+Id34sjXp0POPedrlzcoAkQkL1oDp0 76Z4UM31uplIy/lYuZm261384n6khXXw8A0NCNSI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728435AbgHOXWb (ORCPT ); Sat, 15 Aug 2020 19:22:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:35298 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726021AbgHOXWa (ORCPT ); Sat, 15 Aug 2020 19:22:30 -0400 Received: from localhost (104.sub-72-107-126.myvzw.com [72.107.126.104]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 739D82065C; Sat, 15 Aug 2020 23:22:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597533749; bh=SB9wxVHgt3m7T/tEhx/Oa+YJt9VN49b1ddeU7NMOvEk=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=aVN9qcq6cqmxvD4IsLLewly56VryrzoOr3d3eGSPE1tXpVvGPQOKs97rPBlll36uG 7bM0cxwtJTA4bjf/rGTjcr8A0Xrcoy9KS/l92ag5S/On003FKZrPumPtta4UJtBrD7 ghyyujWRbGVHMF1kSphFqAtvcGhXkHRpnPPnx+L8= Date: Sat, 15 Aug 2020 18:22:28 -0500 From: Bjorn Helgaas To: Marc Zyngier Cc: linux-pci@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Rob Herring , Lorenzo Pieralisi , Heiko Stuebner , Shawn Lin , Roh Herring , Bjorn Helgaas , kernel-team@android.com Subject: Re: [PATCH 1/2] PCI: rockchip: Work around missing device_type property in DT Message-ID: <20200815232228.GA1325245@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200815125112.462652-2-maz@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 15, 2020 at 01:51:11PM +0100, Marc Zyngier wrote: > Recent changes to the DT PCI bus parsing made it mandatory for > device tree nodes describing a PCI controller to have the > 'device_type = "pci"' property for the node to be matched. > > Although this follows the letter of the specification, it > breaks existing device-trees that have been working fine > for years. Rockchip rk3399-based systems are a prime example > of such collateral damage, and have stopped discovering their > PCI bus. > > In order to paper over the blunder, let's add a workaround > to the pcie-rockchip driver, adding the missing property when > none is found at boot time. A warning will hopefully nudge the > user into updating their DT to a fixed version if they can, but > the insentive is obviously pretty small. s/insentive/incentive/ (Lorenzo or I can fix this up) > Fixes: 2f96593ecc37 ("of_address: Add bus type match for pci ranges parser") > Suggested-by: Roh Herring s/Roh/Rob/ (similarly) > Signed-off-by: Marc Zyngier This looks like a candidate for v5.9, since 2f96593ecc37 was merged during the v5.9 merge window, right? I wonder how many other DTs are similarly broken? Maybe Rob's DT checker has already looked? > --- > drivers/pci/controller/pcie-rockchip-host.c | 29 +++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c > index 0bb2fb3e8a0b..d7dd04430a99 100644 > --- a/drivers/pci/controller/pcie-rockchip-host.c > +++ b/drivers/pci/controller/pcie-rockchip-host.c > @@ -949,6 +949,35 @@ static int rockchip_pcie_probe(struct platform_device *pdev) > if (!dev->of_node) > return -ENODEV; > > + /* > + * Most rk3399 DTs are missing the 'device_type = "pci"' property, > + * potentially leading to PCIe probing failure. Be kind to the > + * users and fix it up for them. Upgrading is recommended. > + */ > + if (!of_find_property(dev->of_node, "device_type", NULL)) { > + const char dtype[] = "pci"; > + struct property *prop; > + > + dev_warn(dev, "Working around missing device_type property\n"); > + > + prop = kzalloc(sizeof(*prop), GFP_KERNEL); > + if (!prop) > + return -ENOMEM; > + > + prop->name = kstrdup("device_type", GFP_KERNEL); > + prop->value = kstrdup(dtype, GFP_KERNEL); > + prop->length = ARRAY_SIZE(dtype); > + if (!prop->name || !prop->value) { > + kfree(prop->name); > + kfree(prop->value); > + kfree(prop); > + return -ENOMEM; > + } > + > + if (of_add_property(dev->of_node, prop)) > + dev_warn(dev, "Failed to add property, probing may fail"); > + } > + > bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rockchip)); > if (!bridge) > return -ENOMEM; > -- > 2.27.0 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel