From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Yan Subject: Re: [PATCH v2 6/7] scsi: libsas: reset the phy address if discover failed Date: Thu, 31 Jan 2019 10:13:08 +0800 Message-ID: <5C5259B4.10005@huawei.com> References: <20190130082412.9357-1-yanaijie@huawei.com> <20190130082412.9357-7-yanaijie@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: John Garry , martin.petersen@oracle.com, jejb@linux.vnet.ibm.com Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, zhaohongjiang@huawei.com, hare@suse.com, dan.j.williams@intel.com, jthumshirn@suse.de, hch@lst.de, huangdaode@hisilicon.com, chenxiang66@hisilicon.com, xiexiuqi@huawei.com, tj@kernel.org, miaoxie@huawei.com, Xiaofei Tan , Ewan Milne , Tomas Henzl List-Id: linux-scsi@vger.kernel.org On 2019/1/31 1:36, John Garry wrote: > On 30/01/2019 08:24, Jason Yan wrote: >> When we failed to discover the device, the phy address is still kept >> in ex_phy. So when the next time we revalidate this phy the >> address and device type is the same, it will be considered as flutter >> and will not be discovered again. So the device will not be brought up. >> >> Fix this by reset the phy address to the initial value. Then >> in the next revalidation the device will be discovered agian. > > Why fail to discover the device? I wonder in which scenario you have > seen this, such that it is worth rediscovery. > The test guys have seen this for several times, especially after LLDD changed the logic of lldd_dev_found and may return error now. >> >> Tested-by: Chen Liangfei >> Signed-off-by: Jason Yan >> CC: Xiaofei Tan >> CC: John Garry >> CC: Johannes Thumshirn >> CC: Ewan Milne >> CC: Christoph Hellwig >> CC: Tomas Henzl >> CC: Dan Williams >> CC: Hannes Reinecke >> --- >> drivers/scsi/libsas/sas_expander.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/scsi/libsas/sas_expander.c >> b/drivers/scsi/libsas/sas_expander.c >> index 6e56ebdc2148..e781941a7088 100644 >> --- a/drivers/scsi/libsas/sas_expander.c >> +++ b/drivers/scsi/libsas/sas_expander.c >> @@ -1100,6 +1100,13 @@ static int sas_ex_discover_dev(struct >> domain_device *dev, int phy_id) >> i, SAS_ADDR(ex->ex_phy[i].attached_sas_addr)); >> } >> } >> + } else { >> + /* if we failed to discover this device, we have to >> + * reset the expander phy attached address so that we >> + * will not treat the phy as flutter in the next >> + * revalidation >> + */ >> + memset(ex_phy->attached_sas_addr, 0, SAS_ADDR_SIZE); >> } >> >> return res; >> > > > > . > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20779C282D7 for ; Thu, 31 Jan 2019 02:13:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EAEAD20881 for ; Thu, 31 Jan 2019 02:13:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729937AbfAaCNT (ORCPT ); Wed, 30 Jan 2019 21:13:19 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:58112 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725535AbfAaCNT (ORCPT ); Wed, 30 Jan 2019 21:13:19 -0500 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id C77A5ABD00C1C6F8D9BB; Thu, 31 Jan 2019 10:13:16 +0800 (CST) Received: from [127.0.0.1] (10.177.96.203) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.408.0; Thu, 31 Jan 2019 10:13:10 +0800 Subject: Re: [PATCH v2 6/7] scsi: libsas: reset the phy address if discover failed To: John Garry , , References: <20190130082412.9357-1-yanaijie@huawei.com> <20190130082412.9357-7-yanaijie@huawei.com> CC: , , , , , , , , , , , , Xiaofei Tan , Ewan Milne , Tomas Henzl From: Jason Yan Message-ID: <5C5259B4.10005@huawei.com> Date: Thu, 31 Jan 2019 10:13:08 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.96.203] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/1/31 1:36, John Garry wrote: > On 30/01/2019 08:24, Jason Yan wrote: >> When we failed to discover the device, the phy address is still kept >> in ex_phy. So when the next time we revalidate this phy the >> address and device type is the same, it will be considered as flutter >> and will not be discovered again. So the device will not be brought up. >> >> Fix this by reset the phy address to the initial value. Then >> in the next revalidation the device will be discovered agian. > > Why fail to discover the device? I wonder in which scenario you have > seen this, such that it is worth rediscovery. > The test guys have seen this for several times, especially after LLDD changed the logic of lldd_dev_found and may return error now. >> >> Tested-by: Chen Liangfei >> Signed-off-by: Jason Yan >> CC: Xiaofei Tan >> CC: John Garry >> CC: Johannes Thumshirn >> CC: Ewan Milne >> CC: Christoph Hellwig >> CC: Tomas Henzl >> CC: Dan Williams >> CC: Hannes Reinecke >> --- >> drivers/scsi/libsas/sas_expander.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/scsi/libsas/sas_expander.c >> b/drivers/scsi/libsas/sas_expander.c >> index 6e56ebdc2148..e781941a7088 100644 >> --- a/drivers/scsi/libsas/sas_expander.c >> +++ b/drivers/scsi/libsas/sas_expander.c >> @@ -1100,6 +1100,13 @@ static int sas_ex_discover_dev(struct >> domain_device *dev, int phy_id) >> i, SAS_ADDR(ex->ex_phy[i].attached_sas_addr)); >> } >> } >> + } else { >> + /* if we failed to discover this device, we have to >> + * reset the expander phy attached address so that we >> + * will not treat the phy as flutter in the next >> + * revalidation >> + */ >> + memset(ex_phy->attached_sas_addr, 0, SAS_ADDR_SIZE); >> } >> >> return res; >> > > > > . >