Re: [PATCH 1/2] ata: ahci: Add force LPM policy quirk for ASUS B1400CEAE

Niklas Cassel
2024-02-06T22:07:45Z

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