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Subject: Re: [PATCH v6] libata: Add ATA_HORKAGE_NO_NCQ_ON_ATI for Samsung 860
 and 870 SSD.
To:     Jens Axboe <axboe@kernel.dk>, Kate Hsuan <hpa@redhat.com>,
        Damien Le Moal <damien.lemoal@wdc.com>
Cc:     linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20210903094411.58749-1-hpa@redhat.com>
 <d3488035-d269-2a63-f958-746f371cf490@kernel.dk>
From:   Hans de Goede <hdegoede@redhat.com>
Message-ID: <f1f0b799-6676-ae06-6a71-05dfeeab8512@redhat.com>
Date:   Fri, 3 Sep 2021 16:03:20 +0200
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Hi,

On 9/3/21 2:35 PM, Jens Axboe wrote:
> On 9/3/21 3:44 AM, Kate Hsuan wrote:
>> Many users are reporting that the Samsung 860 and 870 SSD are having
>> various issues when combined with AMD/ATI (vendor ID 0x1002)  SATA
>> controllers and only completely disabling NCQ helps to avoid these
>> issues.
>>
>> Always disabling NCQ for Samsung 860/870 SSDs regardless of the host
>> SATA adapter vendor will cause I/O performance degradation with well
>> behaved adapters. To limit the performance impact to ATI adapters,
>> introduce the ATA_HORKAGE_NO_NCQ_ON_ATI flag to force disable NCQ
>> only for these adapters.
>>
>> Also, two libata.force parameters (noncqati and ncqati) are introduced
>> to disable and enable the NCQ for the system which equipped with ATI
>> SATA adapter and Samsung 860 and 870 SSDs. The user can determine NCQ
>> function to be enabled or disabled according to the demand.
>>
>> After verifying the chipset from the user reports, the issue appears
>> on AMD/ATI SB7x0/SB8x0/SB9x0 SATA Controllers and does not appear on
>> recent AMD SATA adapters. The vendor ID of ATI should be 0x1002.
>> Therefore, ATA_HORKAGE_NO_NCQ_ON_AMD was modified to
>> ATA_HORKAGE_NO_NCQ_ON_ATI.
> 
> What's this patch against?

linux-block/for-next + my pre-cursor patch from here:

https://lore.kernel.org/linux-ide/20210823095220.30157-1-hdegoede@redhat.com/T/#u

Regards,

Hans