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Message-ID: <e95993da-db88-5db2-0aa8-f0c7589ce902@huawei.com>
Date: Tue, 27 Feb 2024 17:42:41 +0800
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Subject: Re: [PATCH] scsi: libsas: Fix disk not being scanned in after being
 removed
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To: John Garry <john.g.garry@oracle.com>, Jason Yan <yanaijie@huawei.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>
 <d765d2c5-3451-4519-a5e1-9e8f28dcd6b3@oracle.com>
 <cdf241a7-8504-5b87-2d18-d2a971f6ebb9@huawei.com>
 <8dc34f04-943b-26fd-01bc-34fb98803503@huawei.com>
 <b2ab5439-361b-4160-4e73-171026ecc486@huawei.com>
 <8138ab55-1c43-8df1-dafd-95b16b7b3ce4@huawei.com>
 <7d132b63-7336-4f59-a5f0-5ec37c3c34d3@oracle.com>
From: yangxingui <yangxingui@huawei.com>
In-Reply-To: <7d132b63-7336-4f59-a5f0-5ec37c3c34d3@oracle.com>
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Hi John,

On 2024/2/27 17:06, John Garry wrote:
> On 27/02/2024 07:16, Jason Yan wrote:
>>>>
>>>> Can we directly set phy->negotiated_linkrate = SAS_PHY_DISABLED 
>>>> here? For an empty PHY the other variables means nothing, so why 
>>>> bother get and update them?
>>> The value of the negotiated link rate has two possible values ​​in 
>>> the current processing branch: SAS_LINK_RATE_UNKNOWN and 
>>> SAS_PHY_DISABLED, and both come from disc_resp. If we do not use 
>>> disc_resp, but set a fixed value SAS_PHY_DISABLED for it, it may not 
>>> be appropriate.
> 
> But we know that the phy is disabled, right? It's our phy, isn't it?
Yes, just like the previous submission, if we disable phy ourselves 
through the sysfs node, we can configure the negotiation rate to 
SAS_PHY_DISABLED by setting phy->phy->enable to 0. It might be better to 
use sas_set_ex_phy() as you described before, it will refresh other phy 
information synchronously, such as sas_address, device_type, 
target_protocols, etc. If we only update the negotiation rate and 
maintain the old information, is it because it is special? Is it better 
to update phy information uniformly?

Thanks,
Xingui