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Subject: Re: [PATCH v4] libata: Add ATA_HORKAGE_NO_NCQ_ON_AMD for Samsung 860
 and 870 SSD.
From:   Hans de Goede <hdegoede@redhat.com>
To:     torvic9@mailbox.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "hpa@redhat.com" <hpa@redhat.com>
Cc:     "linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>,
        "axboe@kernel.dk" <axboe@kernel.dk>,
        "damien.lemoal@wdc.com" <damien.lemoal@wdc.com>
References: <1876334901.51676.1630481868266@office.mailbox.org>
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Message-ID: <2df1c3d5-301d-dc46-7f9f-d28be2933bd3@redhat.com>
Date:   Wed, 1 Sep 2021 11:38:39 +0200
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Hi,

On 9/1/21 10:55 AM, Hans de Goede wrote:
> Hi Tor,
> 
> On 9/1/21 9:37 AM, torvic9@mailbox.org wrote:
>> (Sorry for not doing a proper reply)
>>
>> Hello,
>> Noob here.
>> I have a Samsung 860 Pro connected to a AMD X570 chipset mainboard and
>> it just works flawlessly on 5.13 and 5.14.
>> Are you sure that *every* 860/870 is concerned by this problem on
>> *every* AMD controller?
> 
> I am pretty sure that every 860 / 870 EVO is affected,
> I am not sure if the PRO is also affected.

So while reading https://bugzilla.kernel.org/show_bug.cgi?id=201693
again to add a comment asking if anyone was seeing this on a
pro to I found existing comments of both queued-trims being
an issue on the 860 pro, as well as the 860 pro having issues
with some AMD sata controllers.

So it seems safe to say that the 860 pro has the same issues
as the 860 and 870 evo models. Chances are you don't have
discard support enabled causing you to not see the queued-trim
issues (which means you also won't see any difference from
disabling support for queued-trim commands).

So this just leaves your question of:

"concerned by this problem on *every* AMD controller?"

Where "this problem" is needing to completely disable NCQ
and I guess the answer is no, not every AMD controller
is affected. Still the plan is to err on the safe side for now,
allowing overriding this from the kernel cmdline with:

libata.force=ncqamd

I will add a comment to:

https://bugzilla.kernel.org/show_bug.cgi?id=201693

Asking for PCI-ids of the controllers where people are seeing
this and then maybe we can narrow down the "AMD" check in a
future follow up patch.

Regards,

Hans