From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vNwMc389lzDqBm for ; Thu, 16 Feb 2017 10:23:40 +1100 (AEDT) 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 v1FNJMfA090770 for ; Wed, 15 Feb 2017 18:23:38 -0500 Received: from e23smtp06.au.ibm.com (e23smtp06.au.ibm.com [202.81.31.148]) by mx0a-001b2d01.pphosted.com with ESMTP id 28my2qu784-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 15 Feb 2017 18:23:38 -0500 Received: from localhost by e23smtp06.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 16 Feb 2017 09:23:35 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 9768E2CE805D for ; Thu, 16 Feb 2017 10:23:32 +1100 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v1FNNOl427197670 for ; 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 v1FNN0AD007109 for ; Thu, 16 Feb 2017 10:23:00 +1100 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 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> Message-Id: <1487200954-14681-2-git-send-email-gwshan@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 --- 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); -- 2.7.4