Re: Regression from 7627a0edef54 ("ata: ahci: Drop low power policy board type") on reboot (but not cold boot)

Niklas Cassel
2025-03-13T15:28:44Z

Hello Hans,

On Thu, Mar 13, 2025 at 04:13:24PM +0100, Hans de Goede wrote:
> >
> > Considering that DIPM seems to work fine on the Maxtor drive, I guess your
> > initial suggestion of a Samsung only quirk which only disables LPM on ATI
> > is the best way?
>
> I have no objections against going that route, except that I guess this
> should then be something like ATA_QUIRK_NO_DIPM_ON_ATI to not loose the
> other LPM modes / savings? AFAIK/IIRC there still is quite some powersaving
> to be had without DIPM.

I was thinking like your original suggestion, i.e. setting:
ATA_QUIRK_NO_LPM_ON_ATI

for all the Samsung devices that currently have:
ATA_QUIRK_NO_NCQ_ON_ATI

Considering that this Samsung device only supports DIPM
(and not HIPM), I'm guessing the same is true for the other
Samsung devices as well.

So we might as well just do:
ATA_QUIRK_NO_LPM_ON_ATI

to disable both HIPM and DIPM
(since only DIPM would have been enabled without this quirk anyway).

> Yes the most severe problems do seem to come from that specific mix,
> although the long list of other ATI controller quirks also shows those
> controllers are somewhat finicky.

Definitely!

Kind regards,
Niklas