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; >> > > > > . >