On Wed, Oct 23, 2019 at 7:37 PM Keith Busch <kbusch@xxxxxxxxxx> wrote:
>
> On Wed, Oct 23, 2019 at 12:22:05PM -0700, Olof Johansson wrote:
> > In commit eed85ff4c0da7 ("PCI/DPC: Enable DPC only if AER is available"),
> > the behavior was changed such that native (kernel) handling of DPC
> > got tied to whether the kernel also handled AER. While this is what
> > the standard recommends, there are BIOSes out there that lack the DPC
> > handling since it was never required in the past.
> >
> > To make DPC still work on said platforms the same way they did before,
> > add a "pcie_ports=dpc-native" kernel parameter that can be passed in
> > if needed, while keeping defaults unchanged.
>
> If platform firmware wants to handle AER events, but the kernel enables
> the DPC capability, the ports will be trapping events that firmware is
> expecting to handle. Not that that's a bad thing: firmware is generally
> worse at handling these errors.
Right, and in particular (and what I'm looking for here): It brings
back the older behavior that some platforms rely on. :-/
> > +/*
> > + * If the user specified "pcie_ports=dpc-native", use the PCIe services
> > + * for DPC, but cuse platform defaults for the others.
>
> s/cuse/use
Thanks
> > @@ -1534,9 +1534,11 @@ static inline int pci_irqd_intx_xlate(struct irq_domain *d,
> > #ifdef CONFIG_PCIEPORTBUS
> > extern bool pcie_ports_disabled;
> > extern bool pcie_ports_native;
> > +extern bool pcie_ports_dpc_native;
> > #else
> > #define pcie_ports_disabled true
> > #define pcie_ports_native false
> > +#define pcie_ports_dpc_native false
> > #endif
>
> You do not have any references to pcie_ports_dpc_native outside of files that
> require CONFIG_PCIEPORTBUS, so no need to define a default.
If these are the only comments, maybe Bjorn can fixup when applying.
Bjorn; let me know if you prefer that or if you want a fresh version.
Either is fine with me.
-Olof
