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Subject: Re: [PATCH] scsi: libsas: Fix disk not being scanned in after being
 removed
To: yangxingui <yangxingui@huawei.com>, John Garry <john.g.garry@oracle.com>,
	<jejb@linux.ibm.com>, <martin.petersen@oracle.com>,
	<damien.lemoal@opensource.wdc.com>
CC: <linux-scsi@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linuxarm@huawei.com>, <prime.zeng@hisilicon.com>,
	<chenxiang66@hisilicon.com>, <kangfenglong@huawei.com>
References: <20240221073159.29408-1-yangxingui@huawei.com>
 <f095aa1c-f233-40f9-ad0f-fcd8fe69a80d@oracle.com>
 <e2a725ee-98b3-fd57-6ee4-af031ffbd6bc@huawei.com>
 <80050a50-af6a-5862-8c12-ccaf91c5ff74@huawei.com>
From: Jason Yan <yanaijie@huawei.com>
Message-ID: <7e1b554b-a675-14d2-59aa-7f37e3dd5994@huawei.com>
Date: Tue, 5 Mar 2024 10:56:22 +0800
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On 2024/3/4 20:50, yangxingui wrote:
> Hi Jason,
> 
> On 2024/3/1 9:55, Jason Yan wrote:
>> On 2024/2/29 2:13, John Garry wrote:
>>> On 21/02/2024 07:31, Xingui Yang wrote:
>>>> As of commit d8649fc1c5e4 ("scsi: libsas: Do discovery on empty PHY to
>>>> update PHY info"), do discovery will send a new SMP_DISCOVER and update
>>>> phy->phy_change_count. We found that if the disk is reconnected and phy
>>>> change_count changes at this time, the disk scanning process will 
>>>> not be
>>>> triggered.
>>>>
>>>> So update the PHY info with the last query results.
>>>>
>>>> Fixes: d8649fc1c5e4 ("scsi: libsas: Do discovery on empty PHY to 
>>>> update PHY info")
>>>> Signed-off-by: Xingui Yang <yangxingui@huawei.com>
>>>> ---
>>>>   drivers/scsi/libsas/sas_expander.c | 9 ++++-----
>>>>   1 file changed, 4 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/scsi/libsas/sas_expander.c 
>>>> b/drivers/scsi/libsas/sas_expander.c
>>>> index a2204674b680..9563f5589948 100644
>>>> --- a/drivers/scsi/libsas/sas_expander.c
>>>> +++ b/drivers/scsi/libsas/sas_expander.c
>>>> @@ -1681,6 +1681,10 @@ int sas_get_phy_attached_dev(struct 
>>>> domain_device *dev, int phy_id,
>>>>           if (*type == 0)
>>>>               memset(sas_addr, 0, SAS_ADDR_SIZE);
>>>>       }
>>>> +
>>>> +    if ((SAS_ADDR(sas_addr) == 0) || (res == -ECOMM))
>>>
>>> It's odd to call sas_set_ex_phy() if we got res == -ECOMM. I mean, in 
>>> this this case disc_resp is not filled in as the command did not 
>>> execute, right? I know that is what the current code does, but it is 
>>> strange.
>>
>> The current code actually re-send the SMP command and update the PHY 
>> status only when the the SMP command is responded correctly.
>>
>> Xinggui, can you please fix this and send v3?
> The current location cannot directly update the phy information. The 
> previous phy information will be used later, and the previous sas 
> address will be compared with the currently queried sas address. At 
> present, v2 is more suitable after many days of testing.

OK, so let me have a closer look at v2.

Thanks,
Jason

> 
> Thanks,
> Xingui
> .