[PATCH] nvme-pci: Add suspend quirk for HP mt645 thin client

[Gagniuc, Alexandru]

________________________________________
From: Limonciello, Mario <mario.limonciello at amd.com>
Sent: Friday, July 7, 2023 11:28 PM
To: Gagniuc, Alexandru; linux-nvme at lists.infradead.org
Cc: kbusch at kernel.org; axboe at fb.com; hch at lst.de; sagi at grimberg.me; linux-kernel at vger.kernel.org; Zhang, Eniac; stable at vger.kernel.org
Subject: Re: [PATCH] nvme-pci: Add suspend quirk for HP mt645 thin client

CAUTION: External Email

On 7/6/2023 1:06 PM, Alexandru Gagniuc wrote:
> The HP Elite mt645 thin client exhibits resume times of over one
> minute when using the normal nvme resume path.

Is this the specific product you're referring to?

https://www.amd.com/system/files/documents/hp-elite-mt645-g7-mobile-thin-client.pdf<https://www.amd.com/system/files/documents/hp-elite-mt645-g7-mobile-thin-client.pdf>

> BIOS has tried to work
> around this by setting the "StorageD3Enable" ACPI property, but only
> if it detected the "Linux-HPI-Hybrid-Graphics" _OSI() flag. This flag
> does not exist, so the BIOS workaround can't work.
>
> Instead, just set NVME_QUIRK_SIMPLE_SUSPEND when running on an mt645.
> The DMI_PRODUCT_NAME cannot be used because this string can be changed
> in the field. Match against DMI_BOARD_NAME, which should be immutable.
I'm quite confused why this is necessary.  If the product link
I sent above is correct, this is an AMD Barcelo APU.

Cezanne and Barcelo report as the exact same X86 model.

Cezanne will already always identify as simple
suspend due to bugs that were reported on some other machines.
It's been this way since kernel 6.3-rc1.

e2a56364485e ("ACPI: x86: utils: Add Cezanne to the list for forcing
StorageD3Enable")
[snip]

Hi Mario,

The product link you posted is correct. I was not aware of e2a56364485e
when I developed the fix herein before v6.3. After some quick testing, I can
confirm that e2a56364485e solves the original issue.

We do not need this patch then.

Thank you,
Alex