From patchwork Wed Nov 4 13:12:35 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 539967 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id B360F1402D7 for ; Thu, 5 Nov 2015 01:05:54 +1100 (AEDT) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 999411A3AB9 for ; Thu, 5 Nov 2015 01:05:54 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from e28smtp02.in.ibm.com (e28smtp02.in.ibm.com [122.248.162.2]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 12A221A0D6D for ; Thu, 5 Nov 2015 00:37:47 +1100 (AEDT) Received: from /spool/local by e28smtp02.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 4 Nov 2015 19:07:45 +0530 Received: from d28dlp01.in.ibm.com (9.184.220.126) by e28smtp02.in.ibm.com (192.168.1.132) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 4 Nov 2015 19:07:42 +0530 X-Helo: d28dlp01.in.ibm.com X-MailFrom: gwshan@linux.vnet.ibm.com X-RcptTo: linuxppc-dev@lists.ozlabs.org Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id D1AE5E0054 for ; Wed, 4 Nov 2015 19:07:58 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay05.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id tA4DGnaF45809870 for ; Wed, 4 Nov 2015 19:07:31 +0530 Received: from d28av05.in.ibm.com (localhost [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id tA4DDJa7031360 for ; Wed, 4 Nov 2015 18:43:21 +0530 Received: from gwshan ([9.192.177.12]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with SMTP id tA4DDAOX030585; Wed, 4 Nov 2015 18:43:16 +0530 Received: by gwshan (Postfix, from userid 1000) id 8507B942D01; Thu, 5 Nov 2015 00:13:07 +1100 (AEDT) From: Gavin Shan To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v7 35/50] powerpc/pci: Don't scan empty slot Date: Thu, 5 Nov 2015 00:12:35 +1100 Message-Id: <1446642770-4681-36-git-send-email-gwshan@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1446642770-4681-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1446642770-4681-1-git-send-email-gwshan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15110413-0005-0000-0000-000008839D4D X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, aik@ozlabs.ru, linux-pci@vger.kernel.org, panto@antoniou-consulting.com, Gavin Shan , grant.likely@linaro.org, robherring2@gmail.com, bhelgaas@google.com, frowand.list@gmail.com MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" In hotplug case, function pcibios_add_pci_devices() is called to rescan the specified PCI bus, which might not have any child devices. Access to the PCI bus's child device node will cause kernel crash without exception. This adds condition to skip scanning PCI bus that doesn't have any subordinate devices, in order to avoid kernel crash. Signed-off-by: Gavin Shan --- arch/powerpc/kernel/pci-hotplug.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c index 96e2cc3..825b39c 100644 --- a/arch/powerpc/kernel/pci-hotplug.c +++ b/arch/powerpc/kernel/pci-hotplug.c @@ -120,7 +120,8 @@ void pci_add_pci_devices(struct pci_bus *bus) if (mode == PCI_PROBE_DEVTREE) { /* use ofdt-based probe */ of_rescan_bus(dn, bus); - } else if (mode == PCI_PROBE_NORMAL) { + } else if (mode == PCI_PROBE_NORMAL && + dn->child && PCI_DN(dn->child)) { /* * Use legacy probe. In the partial hotplug case, we * probably have grandchildren devices unplugged. So