Re: [PATCH v3 1/1] PCI/ERR: Fix reset logic in pcie_do_recovery() call

Bjorn Helgaas
2020-09-22T23:33:37Z

On Tue, Sep 22, 2020 at 02:44:51PM -0700, Kuppuswamy, Sathyanarayanan wrote:
>
>
> On 9/22/20 11:52 AM, Bjorn Helgaas wrote:
> > On Fri, Jul 24, 2020 at 12:07:55PM -0700, sathyanarayanan.kuppuswamy@linux.intel.com wrote:
> > > From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> > >
> > > Current pcie_do_recovery() implementation has following two issues:
> > >
> >
> > I'm having trouble parsing this out, probably just lack of my
> > understanding...
> >
> > > 1. Fatal (DPC) error recovery is currently broken for non-hotplug
> > > capable devices. Current fatal error recovery implementation relies
> > > on PCIe hotplug (pciehp) handler for detaching and re-enumerating
> > > the affected devices/drivers. pciehp handler listens for DLLSC state
> > > changes and handles device/driver detachment on DLLSC_LINK_DOWN event
> > > and re-enumeration on DLLSC_LINK_UP event. So when dealing with
> > > non-hotplug capable devices, recovery code does not restore the state
> > > of the affected devices correctly.
> >
> > Apparently in the hotplug case, something *does* restore the state of
> > affected devices?
>
> Yes, in hotplug case, DLLSC state change handler takes over detachment
> /cleanup and re-attachment of affected devices/drivers.

Where does the restore happen here? I.e., what function does this?