From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bh-25.webhostbox.net ([208.91.199.152]:52580 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752863AbbCFQzN (ORCPT ); Fri, 6 Mar 2015 11:55:13 -0500 Received: from mailnull by bh-25.webhostbox.net with sa-checked (Exim 4.82) (envelope-from ) id 1YTvWq-000eRS-TW for linux-pci@vger.kernel.org; Fri, 06 Mar 2015 16:55:13 +0000 Date: Fri, 6 Mar 2015 08:55:04 -0800 From: Guenter Roeck To: Murali Karicheri Cc: Fengguang Wu , Bjorn Helgaas , LKP , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PCI] BUG: unable to handle kernel Message-ID: <20150306165504.GA30094@roeck-us.net> References: <20150306060631.GD28187@wfg-t540p.sh.intel.com> <54F9C407.5020602@ti.com> <54F9CC6B.5070803@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <54F9CC6B.5070803@ti.com> Sender: linux-pci-owner@vger.kernel.org List-ID: On Fri, Mar 06, 2015 at 10:48:59AM -0500, Murali Karicheri wrote: [ ... ] > >From 098b4f5e4ab9407fbdbfcca3a91785c17e25cf03 Mon Sep 17 00:00:00 2001 > From: Murali Karicheri > Date: Fri, 6 Mar 2015 10:23:08 -0500 > Subject: [PATCH] pci: of : fix kernel crash > > This is a debug patch to root cause the kernel crash > > commit 0b2af171520e5d5e7d5b5f479b90a6a5014d9df6 > > PCI: Update DMA configuration from DT > > Signed-off-by: Murali Karicheri > --- > drivers/of/of_pci.c | 8 ++++++++ > drivers/pci/host-bridge.c | 5 +++++ > 2 files changed, 13 insertions(+) > > diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c > index 86d3c38..5a59fb8 100644 > --- a/drivers/of/of_pci.c > +++ b/drivers/of/of_pci.c > @@ -129,6 +129,14 @@ void of_pci_dma_configure(struct pci_dev *pci_dev) > struct device *dev = &pci_dev->dev; > struct device *bridge = pci_get_host_bridge_device(pci_dev); > > + if (!bridge || !bridge->parent) { > + if (!bridge) > + pr_err("PCI bridge not found\n"); > + if (!bridge->parent) > + pr_err("PCI bridge parent not found\n"); You'll see a crash here if bridge is NULL. Maybe add an else before the second if statement ? Also, dev_err might be a bit more useful and would be available. Thanks, Guenter > + return; > + } > + > of_dma_configure(dev, bridge->parent->of_node); > pci_put_host_bridge_device(bridge); > } > diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c > index 3e5bbf9..ef2ab51 100644 > --- a/drivers/pci/host-bridge.c > +++ b/drivers/pci/host-bridge.c > @@ -28,6 +28,11 @@ struct device *pci_get_host_bridge_device(struct pci_dev *dev) > struct pci_bus *root_bus = find_pci_root_bus(dev->bus); > struct device *bridge = root_bus->bridge; > > + if (!bridge) { > + pr_err("PCI: bridge not found\n"); > + return NULL; > + } > + > kobject_get(&bridge->kobj); > return bridge; > } > -- > 1.7.9.5 >