Re: [PATCH v3] PCI: dw-rockchip: Prevent advertising L1 Substates support

Niklas Cassel
2025-11-04T12:30:56Z

Hello Mani,

On Tue, Oct 21, 2025 at 08:02:01AM +0530, Manivannan Sadhasivam wrote:
> On Sat, Oct 18, 2025 at 07:07:35AM +0200, Niklas Cassel wrote:
> > On 17 October 2025 18:45:58 CEST, Bjorn Helgaas <helgaas@kernel.org> wrote:
> >
> > (snip)
> >
> > >>
> > >> Thus, prevent advertising L1 Substates support until proper driver support
> > >> is added.
> > >
> > >I think Mani is planning a change so we don't try to enable L1
> > >Substates by default, which should avoid the regression even without a
> > >patch like this.
> >
> > Sounds good, I suggested the same:
> > https://lore.kernel.org/linux-pci/aO9tWjgHnkATroNa@ryzen/
> >
> >
> > >
> > >That will still leave the existing CONFIG_PCIEASPM_POWER_SUPERSAVE=y
> > >and sysfs l1_1_aspm problems.
> >
> > Indeed, which is why I think that this patch is v6.18 material.
> >
>
> Not strictly a 6.18 material as the Kconfig/sysfs/cmdline issues existed even
> before we enabled the ASPM states by default in v6.18-rc1.

I don't agree that "strictly 6.18 material" means "only fixes for bugs
introduced in the 6.18 merge window".

Normally, for a strict bug fix, the fix is merged during the current
kernel release cycle (rather than waiting for the next merge window),
even if the bug was introduced in an earlier kernel version.

E.g. a fix for a bug introduced during the 6.17 release cycle is
definitely 6.18 material, IMO.

Sure, if the bug is extremely old, that probably means that it is okay
to wait until the next merge window.

In this case, the Fixes tag is a commit first introduced in kernel v5.15,
released Sun Oct 31 13:53:10 2021.

Having that said, I'm perfectly fine with delaying.

Kind regards,
Niklas