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Message-ID: <8498ddc5-e5a5-16b3-bc70-2cfbc79d5258@huawei.com>
Date:   Tue, 22 Mar 2022 11:36:03 +0000
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Subject: Re: [PATCH 03/11] libata: Send internal commands through the block
 layer
To:     Christoph Hellwig <hch@lst.de>
CC:     <axboe@kernel.dk>, <damien.lemoal@opensource.wdc.com>,
        <bvanassche@acm.org>, <jejb@linux.ibm.com>,
        <martin.petersen@oracle.com>, <ming.lei@redhat.com>,
        <hare@suse.de>, <chenxiang66@hisilicon.com>,
        <linux-block@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-ide@vger.kernel.org>, <linux-scsi@vger.kernel.org>,
        <dm-devel@redhat.com>, <beanhuo@micron.com>
References: <1647945585-197349-1-git-send-email-john.garry@huawei.com>
 <1647945585-197349-4-git-send-email-john.garry@huawei.com>
 <20220322112057.GC29270@lst.de>
From:   John Garry <john.garry@huawei.com>
In-Reply-To: <20220322112057.GC29270@lst.de>
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On 22/03/2022 11:20, Christoph Hellwig wrote:
> On Tue, Mar 22, 2022 at 06:39:37PM +0800, John Garry wrote:
>> When SCSI HBA device drivers are required to process an ATA internal
>> command they still need a tag for the IO. This often requires the driver
>> to set aside a set of tags for these sorts of IOs and manage the tags
>> themselves.
>>
>> If we associate a SCSI command (and request) with an ATA internal command
>> then the tag is already provided, so introduce the change to send ATA
>> internal commands through the block layer with a set of custom blk-mq ops.
>>
>> note: I think that the timeout handling needs to be fixed up.
> 
> Any reason to not just send them through an ATA_16 passthrough CDB and
> just use all the normal SCSI command handling?
> 
> .

No reason that I know about.

TBH, I was hoping that someone woud have a better idea on how to do this 
as what I was doing was messy.

Let me check it.

Cheers,
John