[PATCH v1] PCI/AER: Handle Multi UnCorrectable/Correctable errors properly

[Bjorn Helgaas]

On Fri, Mar 11, 2022 at 02:58:07AM +0000, Kuppuswamy Sathyanarayanan wrote:
> Currently the aer_irq() handler returns IRQ_NONE for cases without bits
> PCI_ERR_ROOT_UNCOR_RCV or PCI_ERR_ROOT_COR_RCV are set. But this
> assumption is incorrect.
> 
> Consider a scenario where aer_irq() is triggered for a correctable
> error, and while we process the error and before we clear the error
> status in "Root Error Status" register, if the same kind of error
> is triggered again, since aer_irq() only clears events it saw, the
> multi-bit error is left in tact. This will cause the interrupt to fire
> again, resulting in entering aer_irq() with just the multi-bit error
> logged in the "Root Error Status" register.
> 
> Repeated AER recovery test has revealed this condition does happen
> and this prevents any new interrupt from being triggered. Allow to
> process interrupt even if only multi-correctable (BIT 1) or
> multi-uncorrectable bit (BIT 3) is set.
> 
> Reported-by: Eric Badger <ebadger at purestorage.com>

Is there a bug report with any concrete details (dmesg, lspci, etc)
that we can include here?