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Message-ID: <1b703656-e966-63f8-19dd-33e4e9914676@huawei.com>
Date:   Fri, 5 May 2023 17:14:04 +0800
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Subject: Re: [PATCH v2] ata: libata-scsi: Fix get identity data failed
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To:     John Garry <john.g.garry@oracle.com>,
        Damien Le Moal <dlemoal@kernel.org>, <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>,
        <kangfenglong@huawei.com>
References: <20230505025712.19438-1-yangxingui@huawei.com>
 <291f1d97-9195-45ac-8e12-058f5c797277@kernel.org>
 <b13c9445-39c5-f207-d5d0-d6c86eee54ae@oracle.com>
From:   yangxingui <yangxingui@huawei.com>
In-Reply-To: <b13c9445-39c5-f207-d5d0-d6c86eee54ae@oracle.com>
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On 2023/5/5 16:25, John Garry wrote:
> On 05/05/2023 09:17, Damien Le Moal wrote:
>>> --- a/drivers/ata/libata-scsi.c
>>> +++ b/drivers/ata/libata-scsi.c
>>> @@ -26,6 +26,7 @@
>>>   #include <scsi/scsi_device.h>
>>>   #include <scsi/scsi_tcq.h>
>>>   #include <scsi/scsi_transport.h>
>>> +#include <scsi/libsas.h>
> 
> hmmm... is it really acceptable that libata is referencing libsas? I 
> didn't think that it would be. libsas uses libata, not the other way 
> around.
Yeah, I didn't expect that either. Is there any other way? If so, is 
patch v1 OK?
> 
>>>   #include <linux/libata.h>
>>>   #include <linux/hdreg.h>
>>>   #include <linux/uaccess.h>
>>> @@ -2745,10 +2746,17 @@ static struct ata_device 
>>> *__ata_scsi_find_dev(struct ata_port *ap,
>>>    *    Associated ATA device, or %NULL if not found.
>>>    */
>>>   struct ata_device *
>>> -ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device 
>>> *scsidev)
>> Why drop the const ?
>>
>>> +ata_scsi_find_dev(struct ata_port *ap, struct scsi_device *scsidev)
>>>   {
>>> -    struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev);
>>> +    struct ata_device *dev;
>>> +
>>> +    if (ap->flags & ATA_FLAG_SAS_HOST) {
> 
> And this is SAS host. Not necessarily libsas (even though with ipr 
> libata usage gone, it would be the only user).
Add a new flag only for libsas?

Thanks,
Xingui
.
> 
>>> +        struct domain_device *ddev = sdev_to_domain_dev(scsidev);
>>> +
>>> +        return sas_to_ata_dev(ddev);
>> Do you really need the ddev variable ? Also, this really should be a 
>> libsas
>> helper. I beleive this pattern is repeated in several places in 
>> libsas, so that
>> would nicely clean things up.
>>
> Thanks,
> John
> .