RE: PCI Error Recovery API Proposal. (WAS:: [PATCH/RFC] PCIErrorRecovery)

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

> On a fatal error the interface is down.  No matter what the driver
> supports (AER aware, EEH aware, unaware) all IO is likely to fail.
> Resetting a bus in a point-to-point environment like PCI Express or EEH
> (as you describe) should have little adverse effect.  The risk is the
> bus reset will cause a card reset and the driver must understand to
> re-initialize the card.  A link reset in PCI Express will not cause a
> card reset.  We assume the driver will reset its card if necessary.

Does the link side of PCIE provides a way to trigger a hard reset of the
rest of the card ? If not, then it's dodgy as there may be no way to
consistently "reset" the card if it's in a bad state. I have to double
check, but I suspect that IBM's implementation of EEH-compliant PCIE
will add a full hard reset not just a link reset.