Re: [PATCH] mfd: Fix RTS5227 (and others) powermanagement

[Hans de Goede]

Hi,

On 06-12-17 16:42, Lee Jones wrote:
> On Wed, 06 Dec 2017, Hans de Goede wrote:
>
> > Hi,
> >
> > On 06-12-17 12:21, Hans de Goede wrote:
> > > Commit 8275b77a1513 ("mfd: rts5249: Add support for RTS5250S power
> > > saving") adds powersaving support for device-ids 5249 524a and 525a.
> > >
> > > But as a side effect it breaks ASPM support for all the other device-ids,
> > > causing e.g. the Haswell CPU on a Lenovo T440s to not go into a higher
> > > c-state then PC3, while previously it would go to PC7, causing the
> > > machine to idle at 7.4W instead of 6.6W!
> > >
> > > The problem here is the new option.dev_aspm_mode field, which only gets
> > > explicitly initialized in the new code for the device-ids 5249 524a and
> > > 525a. Leaving the dev_aspm_mode 0 for the other device-ids.
> > >
> > > The default dev_aspm_mode 0 is mapped to DEV_ASPM_DISABLE, but the
> > > old behavior of calling rtsx_pci_enable_aspm() when idle and
> > > rtsx_pci_disable_aspm() when busy happens when dev_aspm_mode ==
> > > DEV_ASPM_DYNAMIC.
> > >
> > > This commit changes the enum so that 0 = DEV_ASPM_DYNAMIC matching the
> > > old default behavior, fixing the pm regression with the other device-ids.
> > >
> > > Cc: Rui Feng <rui_feng@xxxxxxxxxxxxxx>
> > > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> >
> > p.s.
> >
> > 2 remarks:
> >
> > 1. As this is a regression in 4.15, please queue this up as a fix for 4.15
> >     (I prioritized bisecting this, which took me a whole day to get a fix
> >      ready in time for 4.15).
>
> If this is aimed at -the rcs, you should apply a Fixes: tag.

Right, I should have thought of that myself.

> Happy to do it for you this time.

Thanks you.

Regards,

Hans