Re: [PATCH v3] PCI: pciehp: Fix hotplug on Catlow Lake with unreliable PME status

Mika Westerberg
2026-03-25T06:11:34Z

On Tue, Mar 24, 2026 at 02:45:25PM -0700, Kuppuswamy Sathyanarayanan wrote:
> > eb34da60edee ("PCI: pciehp: Disable hotplug interrupt during suspend")
> > cleared PCI_EXP_SLTCTL_HPIE so that when the link goes down, we
> > wouldn't get a PCI_EXP_SLTSTA_DLLSC interrupt and wake the system.
> >
> > I don't know the details of why the PCI_EXP_SLTSTA_DLLSC would cause
> > that wakeup. I would think pciehp should field that, and it should be
> > able to figure out whether to bring the port out of D3hot.
> >
> > Anyway, with this patch it looks like we'll leave PCI_EXP_SLTCTL_HPIE
> > set, and potentially get that PCI_EXP_SLTSTA_DLLSC interrupt again?
>
> I have tested this patch on Catlow Lake. Enabling HPIE does not result in
> spurious wakeups as mentioned in Mika's patch.
>
> Mika, any comments?

What do you have connected to the slot?

IIRC the interrupt triggers when presence change toggles (due to the link
going down).