From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752546AbcFUPlR (ORCPT ); Tue, 21 Jun 2016 11:41:17 -0400 Received: from mail-lf0-f49.google.com ([209.85.215.49]:36365 "EHLO mail-lf0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751899AbcFUPlP (ORCPT ); Tue, 21 Jun 2016 11:41:15 -0400 Date: Tue, 21 Jun 2016 18:41:00 +0300 From: Valentine Barshak To: Bjorn Helgaas Cc: Geert Uytterhoeven , Bjorn Helgaas , linux-pci@vger.kernel.org, Thomas Petazzoni , Rob Herring , Jason Cooper , Scott Branden , Jon Mason , Jingoo Han , Pratyush Anand , linux-kernel@vger.kernel.org, rfi@lists.rocketboards.org, linux-renesas-soc@vger.kernel.org, Simon Horman , Thierry Reding , Tanmay Inamdar , Ray Jui , linux-tegra@vger.kernel.org, Ley Foon Tan , Michal Simek , =?iso-8859-1?Q?S=F6ren?= Brinkmann , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v1 19/25] PCI: rcar Gen2: Request host bridge window resources Message-ID: <20160621154100.GA4782@cogentembedded.com> Reply-To: Valentine Barshak References: <20160606225630.20936.77349.stgit@bhelgaas-glaptop2.roam.corp.google.com> <20160606230706.20936.13086.stgit@bhelgaas-glaptop2.roam.corp.google.com> <20160621142623.GA29966@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160621142623.GA29966@localhost> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 21, 2016 at 09:26:23AM -0500, Bjorn Helgaas wrote: > [+cc Valentine] > Hi Bjorn, > Hi Geert, > > Thanks a lot for testing this, and sorry for the breakage. > > On Tue, Jun 21, 2016 at 12:41:31PM +0200, Geert Uytterhoeven wrote: > > On Tue, Jun 7, 2016 at 1:07 AM, Bjorn Helgaas wrote: > > > Request host bridge window resources so they appear in ioport_resource and > > > iomem_resource and are reflected in /proc/ioports and /proc/iomem. > > > > > > Signed-off-by: Bjorn Helgaas > > > --- > > > drivers/pci/host/pci-rcar-gen2.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c > > > index 9980a4b..617a6b2 100644 > > > --- a/drivers/pci/host/pci-rcar-gen2.c > > > +++ b/drivers/pci/host/pci-rcar-gen2.c > > > @@ -194,6 +194,7 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys) > > > struct rcar_pci_priv *priv = sys->private_data; > > > void __iomem *reg = priv->reg; > > > u32 val; > > > + int ret; > > > > > > pm_runtime_enable(priv->dev); > > > pm_runtime_get_sync(priv->dev); > > > @@ -275,6 +276,9 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys) > > > /* Add PCI resources */ > > > pci_add_resource(&sys->resources, &priv->io_res); > > > pci_add_resource(&sys->resources, &priv->mem_res); > > > + ret = devm_request_pci_bus_resources(priv->dev, &sys->resources); > > > + if (ret < 0) > > > + return ret; > > > > > > /* Setup bus number based on platform device id / of bus-range */ > > > sys->busnr = priv->busnr; > > > > This patch (commit 1bd019707b7c9249d34c5d348f1ef75eb4d83e89 in pci/next) > > broke PCI on r8a7791/koelsch. Dmesg differences are: > > > > pci-rcar-gen2 ee090000.pci: PCI: bus0 revision 11 > > -pci-rcar-gen2 ee090000.pci: PCI host bridge to bus 0000:00 > > -pci_bus 0000:00: root bus resource [io 0xee080000-0xee0810ff] > > -pci_bus 0000:00: root bus resource [mem 0xee080000-0xee0810ff] > > This is probably a result of this code in drivers/pci/host/pci-rcar-gen2.c: > > /* > * The controller does not support/use port I/O, > * so setup a dummy port I/O region here. > */ > priv->io_res.start = priv->mem_res.start; > priv->io_res.end = priv->mem_res.end; > priv->io_res.flags = IORESOURCE_IO; > > We try to avoid adding dummy regions like this, but maybe we missed > this one. I haven't found any email discussion about it yet, so I > don't know what the reason for this one is. Valentine, do you > remember? I do not, but I think I've found something in my mailbox. Below is the quote from the original conversation with: (Re: [PATCH] pci: Add R-Car Gen2 internal PCI support) [quote starts] >>+ priv->mem_res = *mem_res; >>+ /* >>+ * The controller does not support/use port I/O, >>+ * so setup a dummy port I/O region here. >>+ */ >>+ priv->io_res.start = priv->mem_res.start; >>+ priv->io_res.end = priv->mem_res.end; >>+ priv->io_res.flags = IORESOURCE_IO; >> > I don't understand this. There's no requirement (at least as far as the > PCI core is concerned) to supply an I/O aperture at all, and I think it > would be better if you didn't. > > Oh, I see ... maybe pcibios_init_resources() forces you to have an > I/O resource to avoid having it give you a default one? And I > suppose that since you have several host bridges, these dummy I/O > regions have to be distinct. Ugh. Well, I guess this is something > you'd have to fix here or in the ARM code, it's up to you what to do. Exactly. This is to avoid assigning default I/O resources. [quote ends] > > Can you try the patch below (apply it before the 1bd019707b7c patch > that broke things)? > > > commit b64dc28f5f2b3afe47ee4a42fb79db84ec4227f8 > Author: Bjorn Helgaas > Date: Tue Jun 21 09:19:34 2016 -0500 > > PCI: rcar: Drop gen2 dummy I/O port region > > Previously we added a dummy I/O port region even though the R-Car > controller doesn't support PCI port I/O. This resulted in bogus root bus > resources like this: > > pci_bus 0000:00: root bus resource [io 0xee080000-0xee0810ff] > pci_bus 0000:00: root bus resource [mem 0xee080000-0xee0810ff] > > Drop the unused dummy I/O port region. > > Signed-off-by: Bjorn Helgaas > > diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c > index 9980a4b..53ae619 100644 > --- a/drivers/pci/host/pci-rcar-gen2.c > +++ b/drivers/pci/host/pci-rcar-gen2.c > @@ -97,7 +97,6 @@ > struct rcar_pci_priv { > struct device *dev; > void __iomem *reg; > - struct resource io_res; > struct resource mem_res; > struct resource *cfg_res; > unsigned busnr; > @@ -273,7 +272,6 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys) > rcar_pci_setup_errirq(priv); > > /* Add PCI resources */ > - pci_add_resource(&sys->resources, &priv->io_res); > pci_add_resource(&sys->resources, &priv->mem_res); > > /* Setup bus number based on platform device id / of bus-range */ > @@ -371,14 +369,6 @@ static int rcar_pci_probe(struct platform_device *pdev) > return -ENOMEM; > > priv->mem_res = *mem_res; > - /* > - * The controller does not support/use port I/O, > - * so setup a dummy port I/O region here. > - */ > - priv->io_res.start = priv->mem_res.start; > - priv->io_res.end = priv->mem_res.end; > - priv->io_res.flags = IORESOURCE_IO; > - > priv->cfg_res = cfg_res; > > priv->irq = platform_get_irq(pdev, 0); -- Thanks, Val.