From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3yqsjH5qGzzDrbr for ; Mon, 4 Dec 2017 15:44:19 +1100 (AEDT) From: Michael Ellerman To: Bjorn Helgaas , linux-pci@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Christian Zigotzky Subject: Re: [PATCH v1] PCI: Make PCI_SCAN_ALL_PCIE_DEVS work for Root as well as Downstream Ports In-Reply-To: <20171202191827.GB18780@bhelgaas-glaptop.roam.corp.google.com> References: <20171202002710.17686.21340.stgit@bhelgaas-glaptop.roam.corp.google.com> <20171202191827.GB18780@bhelgaas-glaptop.roam.corp.google.com> Date: Mon, 04 Dec 2017 15:44:15 +1100 Message-ID: <87k1y33xwg.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Bjorn Helgaas writes: > On Fri, Dec 01, 2017 at 06:27:10PM -0600, Bjorn Helgaas wrote: >> From: Bjorn Helgaas >> >> PCIe Downstream Ports normally have only a Device 0 below them. To >> optimize enumeration, we don't scan for other devices *unless* the >> PCI_SCAN_ALL_PCIE_DEVS flag is set by set by quirks or the >> "pci=pcie_scan_all" kernel parameter. >> >> Previously PCI_SCAN_ALL_PCIE_DEVS only affected scanning below Switch >> Downstream Ports, not Root Ports. >> >> But the "Nemo" system, also known as the AmigaOne X1000, has a PA Semi Root >> Port whose link leads to an AMD/ATI SB600 South Bridge. The Root Port is a >> PCIe device, of course, but the SB600 contains only conventional PCI >> devices with no visible PCIe port. >> >> Simplify and restructure only_one_child() so that we scan for all possible >> devices below Root Ports as well as Switch Downstream Ports when >> PCI_SCAN_ALL_PCIE_DEVS is set. >> >> This is enough to make Nemo work with "pci=pcie_scan_all". We would also >> like to add a quirk to set PCI_SCAN_ALL_PCIE_DEVS automatically on Nemo so >> users wouldn't have to use the "pci=pcie_scan_all" parameter, but we don't >> have that yet. >> >> Link: https://lkml.kernel.org/r/CAErSpo55Q8Q=5p6_+uu7ahnw+53ibVDNRXxrzRV9QnUr_9EUfw@mail.gmail.com >> Link: https://bugzilla.kernel.org/show_bug.cgi?id=198057 >> Reported-and-Tested-by: Christian Zigotzky >> Signed-off-by: Bjorn Helgaas > > Applied to pci/enumeration for v4.16. Thanks Bjorn. cheers