From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bear.ext.ti.com ([192.94.94.41]:43569 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751278AbbCFR6I (ORCPT ); Fri, 6 Mar 2015 12:58:08 -0500 Message-ID: <54F9EAA8.30007@ti.com> Date: Fri, 6 Mar 2015 12:58:00 -0500 From: Murali Karicheri MIME-Version: 1.0 To: Guenter Roeck CC: Fengguang Wu , Bjorn Helgaas , LKP , , Subject: Re: [PCI] BUG: unable to handle kernel References: <20150306060631.GD28187@wfg-t540p.sh.intel.com> <54F9C407.5020602@ti.com> <54F9CC6B.5070803@ti.com> <20150306165504.GA30094@roeck-us.net> In-Reply-To: <20150306165504.GA30094@roeck-us.net> Content-Type: multipart/mixed; boundary="------------030700000309030004040609" Sender: linux-pci-owner@vger.kernel.org List-ID: --------------030700000309030004040609 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit On 03/06/2015 11:55 AM, Guenter Roeck wrote: > 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. > Fixed and attached. Murali > 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 >> > -- Murali Karicheri Linux Kernel, Texas Instruments --------------030700000309030004040609 Content-Type: text/x-diff; name="0001-pci-of-fix-kernel-crash.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="0001-pci-of-fix-kernel-crash.patch" >>From 4965a4580e0ffe13e7e6e9fd58d6e56b08c730c4 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 | 9 +++++++++ drivers/pci/host-bridge.c | 5 +++++ 2 files changed, 14 insertions(+) diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index 86d3c38..6e1b111 100644 --- a/drivers/of/of_pci.c +++ b/drivers/of/of_pci.c @@ -129,6 +129,15 @@ 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) + dev_err(&pci_dev->dev, "PCI bridge not found\n"); + else if (!bridge->parent) + dev_err(&pci_dev->dev, + "PCI bridge parent not found\n"); + 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..ba642b8 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) { + dev_err(&dev->dev, "PCI: bridge not found\n"); + return NULL; + } + kobject_get(&bridge->kobj); return bridge; } -- 1.7.9.5 --------------030700000309030004040609--