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Date: Tue, 6 Feb 2024 23:07:38 +0100
From: Niklas Cassel <cassel@kernel.org>
To: Jian-Hong Pan <jhp@endlessos.org>,
	Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Drake <drake@endlessos.org>,
	Vitalii Solomonov <solomonov.v@gmail.com>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	David Box <david.e.box@linux.intel.com>,
	Damien Le Moal <dlemoal@kernel.org>,
	Nirmal Patel <nirmal.patel@linux.intel.com>,
	Jonathan Derrick <jonathan.derrick@linux.dev>,
	linux-ide@vger.kernel.org, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux@endlessos.org
Subject: Re: [PATCH 1/2] ata: ahci: Add force LPM policy quirk for ASUS
 B1400CEAE
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In-Reply-To: <ZcIwMb0WPZLG85LR@x1-carbon>

On Tue, Feb 06, 2024 at 02:12:17PM +0100, Niklas Cassel wrote:
> On Tue, Feb 06, 2024 at 04:39:02PM +0800, Jian-Hong Pan wrote:
> > Niklas Cassel <cassel@kernel.org> 於 2024年2月5日 週一 下午7:33寫道：

(snip)

> 
> It seems that at least Intel AHCI controllers that also have Intel VMD
> enabled break when this quirk is applied.
> 
> I guess one way would be to do a:
> git show c312ef176399:drivers/ata/ahci.c | grep "PCI_VDEVICE(INTEL"
> and replace everything that is not: board_ahci_pcs7
> with a board_ahci_pcs_quirk, board_ahci_low_power_pcs_quirk, and
> board_ahci_avn_pcs_quirk, and after that change all board_ahci_pcs7
> entries to board_ahci, and assume that entries added since c312ef176399
> do not need the quirk.
> 
> But it would be nice if someone from Intel could clean this up.

While it would still be nice if someone cleaned up the intel_pcs_quirk.


Jian-Hong, perhaps you can try my series:
https://lore.kernel.org/linux-ide/20240206211352.1664816-1-cassel@kernel.org/

Also available here:
https://github.com/floatious/linux/tree/external-port-v2

With that series, you should not need an explicit "board_ahci_low_power"
entry for Tiger Lake to get working LPM.

If fact, you want to ensure that you do not have any Tiger Lake entry in
ahci_pci_tbl, as that will apply intel_pcs_quirk and break your platform.

Testing is appreciated :)

Let's hope that LPM is enabled and that you can also enter low-power
C-states.


Kind regards,
Niklas