Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755497AbbHNQna (ORCPT ); Fri, 14 Aug 2015 12:43:30 -0400 Received: from foss.arm.com ([217.140.101.70]:39456 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755104AbbHNQn2 (ORCPT ); Fri, 14 Aug 2015 12:43:28 -0400 Date: Fri, 14 Aug 2015 17:43:25 +0100 From: Will Deacon To: Bjorn Helgaas Cc: Marc Zyngier , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , "suravee.suthikulpanit@amd.com" , Lorenzo Pieralisi , "grant.likely@linaro.org" , Rob Herring , "agraf@suse.de" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-pci@vger.kernel.org" , "devicetree@vger.kernel.org" Subject: Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property Message-ID: <20150814164324.GC22809@arm.com> References: <1439569159-10051-1-git-send-email-marc.zyngier@arm.com> <1439569159-10051-3-git-send-email-marc.zyngier@arm.com> <20150814164051.GF26431@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150814164051.GF26431@google.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2519 Lines: 61 On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote: > On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote: > > When pci-host-generic looks for the probe-only property, it seems > > to trust the DT to be correctly written, and assumes that there > > is a parameter to the property. > > > > Unfortunately, this is not always the case, and some firmware expose > > this property naked. The driver ends up making a decision based on > > whatever the property pointer points to, which is likely to be junk. > > > > Switch to the common of_pci.c implementation that doesn't suffer > > from this problem. > > > > Signed-off-by: Marc Zyngier > > --- > > drivers/pci/host/pci-host-generic.c | 9 +-------- > > 1 file changed, 1 insertion(+), 8 deletions(-) > > > > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > > index 265dd25..545ff4e 100644 > > --- a/drivers/pci/host/pci-host-generic.c > > +++ b/drivers/pci/host/pci-host-generic.c > > @@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev) > > int err; > > const char *type; > > const struct of_device_id *of_id; > > - const int *prop; > > struct device *dev = &pdev->dev; > > struct device_node *np = dev->of_node; > > struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL); > > @@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev) > > return -EINVAL; > > } > > > > - prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL); > > - if (prop) { > > - if (*prop) > > - pci_add_flags(PCI_PROBE_ONLY); > > - else > > - pci_clear_flags(PCI_PROBE_ONLY); > > - } > > + of_pci_check_probe_only(of_chosen); > > Do we need support for pci-probe-only in pci-host-generic at all? > You're removing the use in amd-overdrive.dts, and there are no other > DTs in the kernel tree that mention it. > > If we can live without it, that would be nice. It seems like a relic from > days when we couldn't reliably assign resources. (I'm not saying we can do > that reliably even today, but I'd rather make it reliable than turn it > off.) Kvmtool certainly uses it (and generates its own DT, hence why you don't see it in mainline). Not sure about qemu, though. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/