Re: [PATCH 2/2] PCI: amd-mdb: Add AMD MDB Root Port driver

["manivannan.sadhasivam@linaro.org" <manivannan.sadhasivam@linaro.org>]

On Mon, Dec 02, 2024 at 08:21:36AM +0000, Havalige, Thippeswamy wrote:

[...]

> > > +	d = irq_domain_get_irq_data(pcie->mdb_domain, irq);
> > > +	if (intr_cause[d->hwirq].str)
> > > +		dev_warn(dev, "%s\n", intr_cause[d->hwirq].str);
> > > +	else
> > > +		dev_warn(dev, "Unknown IRQ %ld\n", d->hwirq);
> > > +
> > > +	return IRQ_HANDLED;
> > 
> > I see that some of these messages are "Correctable/Non-Fatal/Fatal error
> > message"; I assume this Root Port doesn't have an AER Capability, and this
> > interrupt is the "System Error" controlled by the Root Control Error Enable bits in the
> > PCIe Capability?  (See PCIe r6.0, sec 6.2.6)
> > 
> > Is there any way to hook this into the AER handling so we can do something about
> > it, since the devices *below* the Root Port may support AER and may have useful
> > information logged?
> > 
> > Since this is DWC-based, I suppose these are general questions that apply to all
> > the similar drivers.
> 
> 
> Thanks for review, We have this in our plan to hook platform specific error interrupts 
> to AER in future will add this support.
> 

So on your platform, AER (also PME) interrupts are reported over SPI interrupt
only and not through MSI/MSI-X? Most of the DWC controllers have this weird
behavior of reporting AER/PME only through SPI, but that should be legacy
controllers. Newer ones does support MSI.

- Mani

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