From patchwork Wed Feb 15 23:22:32 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 9575837 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DAC31601D8 for ; Wed, 15 Feb 2017 23:54:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C8C8228598 for ; Wed, 15 Feb 2017 23:54:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BA2172859B; Wed, 15 Feb 2017 23:54:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AAB662848F for ; Wed, 15 Feb 2017 23:54:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754230AbdBOXyL (ORCPT ); Wed, 15 Feb 2017 18:54:11 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:53741 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755053AbdBOXXk (ORCPT ); Wed, 15 Feb 2017 18:23:40 -0500 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1FNJLFB090692 for ; Wed, 15 Feb 2017 18:23:39 -0500 Received: from e23smtp01.au.ibm.com (e23smtp01.au.ibm.com [202.81.31.143]) by mx0a-001b2d01.pphosted.com with ESMTP id 28my2qu78d-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 15 Feb 2017 18:23:39 -0500 Received: from localhost by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 16 Feb 2017 09:23:33 +1000 Received: from d23relay06.au.ibm.com (d23relay06.au.ibm.com [9.185.63.219]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id B4143357805A; Thu, 16 Feb 2017 10:23:32 +1100 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay06.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v1FNNOF522872246; Thu, 16 Feb 2017 10:23:32 +1100 Received: from d23av04.au.ibm.com (localhost [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v1FNN0AF007109; Thu, 16 Feb 2017 10:23:00 +1100 Received: from ozlabs.au.ibm.com (ozlabs.au.ibm.com [9.192.253.14]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id v1FNN0FV006709; Thu, 16 Feb 2017 10:23:00 +1100 Received: from bran.ozlabs.ibm.com (haven.au.ibm.com [9.192.254.114]) by ozlabs.au.ibm.com (Postfix) with ESMTP id A399DA0212; Thu, 16 Feb 2017 10:22:35 +1100 (AEDT) Received: from gwshan.ozlabs.ibm.com (shangw.ozlabs.ibm.com [10.61.2.199]) by bran.ozlabs.ibm.com (Postfix) with ESMTP id 96456E3D4F; Thu, 16 Feb 2017 10:22:35 +1100 (AEDT) Received: by gwshan.ozlabs.ibm.com (Postfix, from userid 1000) id 8C1EDAC309D; Thu, 16 Feb 2017 10:22:35 +1100 (AEDT) From: Gavin Shan To: linuxppc-dev@lists.ozlabs.org Cc: linux-pci@vger.kernel.org, mpe@ellerman.id.au, bhelgaas@google.com, Gavin Shan , "# v4 . 8+" Subject: [PATCH 1/3] pci/hotplug/pnv-php: Remove WARN_ON() in pnv_php_put_slot() Date: Thu, 16 Feb 2017 10:22:32 +1100 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1487200954-14681-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1487200954-14681-1-git-send-email-gwshan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17021523-1617-0000-0000-000001A8A40C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17021523-1618-0000-0000-000047BD9320 Message-Id: <1487200954-14681-2-git-send-email-gwshan@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-02-15_12:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=3 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1702150211 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The WARN_ON() causes unnecessary backtrace when putting the parent slot, which is likely to be NULL. WARNING: CPU: 2 PID: 1071 at drivers/pci/hotplug/pnv_php.c:85 \ pnv_php_release+0xcc/0x150 [pnv_php] : Call Trace: [c0000003bc007c10] [d00000000ad613c4] pnv_php_release+0x144/0x150 [pnv_php] [c0000003bc007c40] [c0000000006641d8] pci_hp_deregister+0x238/0x330 [c0000003bc007cd0] [d00000000ad61440] pnv_php_unregister_one+0x70/0xa0 [pnv_php] [c0000003bc007d10] [d00000000ad614c0] pnv_php_unregister+0x50/0x80 [pnv_php] [c0000003bc007d40] [d00000000ad61e84] pnv_php_exit+0x50/0xcb4 [pnv_php] [c0000003bc007d70] [c00000000019499c] SyS_delete_module+0x1fc/0x2a0 [c0000003bc007e30] [c00000000000b184] system_call+0x38/0xe0 Cc: # v4.8+ Fixes: 66725152fb9f ("PCI/hotplug: PowerPC PowerNV PCI hotplug driver") Signed-off-by: Gavin Shan Reviewed-by: Andrew Donnellan Tested-by: Vaibhav Jain --- drivers/pci/hotplug/pnv_php.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 63cd9f3..da1bbf3 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -76,7 +76,7 @@ static void pnv_php_free_slot(struct kref *kref) static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot) { - if (WARN_ON(!php_slot)) + if (!php_slot) return; kref_put(&php_slot->kref, pnv_php_free_slot);