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Subject: Re: arm scsi drivers
To:     Hannes Reinecke <hare@suse.de>,
        "Russell King (Oracle)" <linux@armlinux.org.uk>
CC:     "Martin K . Petersen" <martin.petersen@oracle.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Hannes Reinecke <hare@suse.com>,
        "Christoph Hellwig" <hch@lst.de>,
        Bart Van Assche <bvanassche@acm.org>,
        Arnd Bergmann <arnd@arndb.de>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>
References: <5a72842f-99db-8787-120b-6d85e7884e2d@huawei.com>
 <9552a506-e53a-3fd3-b38e-3cec81e713a6@huawei.com>
 <20210827150938.GU22278@shell.armlinux.org.uk>
 <087d1fa0-8796-5b97-36fc-379498f53380@suse.de>
From:   John Garry <john.garry@huawei.com>
Message-ID: <cbd7991e-0634-83c1-0a6a-c834324ec72d@huawei.com>
Date:   Wed, 1 Sep 2021 09:03:28 +0100
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On 27/08/2021 16:23, Hannes Reinecke wrote:
> On 8/27/21 5:09 PM, Russell King (Oracle) wrote:
>> I haven't, sorry.
>>
>> I have run 5.x kernels on the hardware, and do have a set of patches
>> kicking around for the SCSI drivers that do some cleanups. It looks
>> like the fixup is pretty simple from the links you've sent - using
>> scsi_cmd_to_rq() to get the tag.

I'm not sure. The SCSI midlayer does nothing with that tag field, apart 
from set it to the block layer request tag, and it seems that these 
drivers reuse that field for their own tag management. But Hannes is 
confident that we may just use scsi_cmd_to_rq().

>>
>> That said, I think I may only had one SCSI drive that came anywhere
>> close to supported tagged queuing, so I never put much effort into
>> tagged command support. Both acornscsi and fas216 have it disabled
>> for this reason, so it's probably easier just to rip the tag code
>> out of these drivers.
>>
> That's what I figured, too.
> And that's what my patches do, killing the tag support from arm drivers 
> which had them disabled since the dawn of git history.

These are the patches:
https://lore.kernel.org/linux-scsi/20210819084007.79233-1-hare@suse.de/T/#t

Hannes, please consider resending, cc'ing Russell.

Thanks,
John