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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 3FC3BECE567 for ; Fri, 21 Sep 2018 16:07:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0326E21557 for ; Fri, 21 Sep 2018 16:07:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0326E21557 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390605AbeIUV5Z (ORCPT ); Fri, 21 Sep 2018 17:57:25 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:38688 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389545AbeIUV5Y (ORCPT ); Fri, 21 Sep 2018 17:57:24 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2320418A; Fri, 21 Sep 2018 09:07:51 -0700 (PDT) Received: from e107981-ln.cambridge.arm.com (e107981-ln.Emea.Arm.com [10.4.13.117]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0E4363F557; Fri, 21 Sep 2018 09:07:47 -0700 (PDT) Date: Fri, 21 Sep 2018 17:07:45 +0100 From: Lorenzo Pieralisi To: honghui.zhang@mediatek.com Cc: marc.zyngier@arm.com, bhelgaas@google.com, matthias.bgg@gmail.com, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, yingjoe.chen@mediatek.com, eddie.huang@mediatek.com, ryder.lee@mediatek.com, ulf.hansson@linaro.org, hongkun.cao@mediatek.com, youlin.pei@mediatek.com, yong.wu@mediatek.com, yt.shen@mediatek.com, sean.wang@mediatek.com, xinping.qian@mediatek.com Subject: Re: [PATCH v4 1/4] PCI: mediatek: fixup mtk_pcie_find_port logical Message-ID: <20180921160745.GB21644@e107981-ln.cambridge.arm.com> References: <1536573023-6720-1-git-send-email-honghui.zhang@mediatek.com> <1536573023-6720-2-git-send-email-honghui.zhang@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1536573023-6720-2-git-send-email-honghui.zhang@mediatek.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 10, 2018 at 05:50:20PM +0800, honghui.zhang@mediatek.com wrote: > From: Honghui Zhang > > The Mediatek's host controller has two slots, each with it's own control > registers. The host driver need to identify which slot was connected > in order to access the device's configuration space. There's problem > for current host driver to find out which slot was connected to for > a given EP device. > > Assuming each slot have connect with one EP device as below: > > host bridge > bus 0 --> __________|_______ > | | > | | > slot 0 slot 1 > bus 1 -->| bus 2 --> | > | | > EP 0 EP 1 > > During PCI enumeration, system software will scan all the PCI device > starting from devfn 0. So it will get the proper port for slot0 and > slot1 device when using PCI_SLOT(devfn) for match. But it will get > the wrong slot for EP1: The devfn will be start from 0 when scanning > EP1 behind slot1, it will get port0 since the PCI_SLOT(EP1) is match > for port0's slot value. So the host driver should not using EP's devfn > but the slot's devfn(the slot which EP was connected to) for match. > > This patch fix the mtk_pcie_find_port's logical by using the slot's > devfn for match. > > Signed-off-by: Honghui Zhang > Acked-by: Ryder Lee > --- > drivers/pci/controller/pcie-mediatek.c | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c > index 861dda6..20b9088 100644 > --- a/drivers/pci/controller/pcie-mediatek.c > +++ b/drivers/pci/controller/pcie-mediatek.c > @@ -337,11 +337,26 @@ static struct mtk_pcie_port *mtk_pcie_find_port(struct pci_bus *bus, > { > struct mtk_pcie *pcie = bus->sysdata; > struct mtk_pcie_port *port; > + struct pci_dev *dev; > + struct pci_bus *pbus; > > - list_for_each_entry(port, &pcie->ports, list) > - if (port->slot == PCI_SLOT(devfn)) > + list_for_each_entry(port, &pcie->ports, list) { > + if (!bus->number && port->slot == PCI_SLOT(devfn)) > return port; > > + if (bus->number) { > + pbus = bus; > + > + while (pbus->number) { > + dev = pbus->self; > + pbus = dev->bus; > + } > + > + if (port->slot == PCI_SLOT(dev->devfn)) > + return port; > + } > + } /* * Walk the bus hierarchy to get the devfn value * of the port in the root bus. */ while (bus && bus->number) { devfn = bus->self->devfn; bus = bus->parent; } list_for_each_entry(port, &pcie->ports, list) { if (port->slot == PCI_SLOT(devfn)) return port; return NULL; Would it work ? Maybe it is a little easier to parse. I think this can even be made easier by using struct device_node* as comparison (and store it in port->slot instead of the port number), I think that the pci_dev representing the port should have the right of_node associated with it by core code, so it is just a matter of finding the first pci_dev parent with an of_node set and compare it against port->slot (that should be converted to a struct device_node*). This ought to be tested and written but I think that's doable. Lorenzo