Re: [PATCH v2] PCI/AER: Handle Multi UnCorrectable/Correctable errors properly

[Sathyanarayanan Kuppuswamy]

On 3/15/22 10:14 AM, Eric Badger wrote:
> >   # Prep injection data for a correctable error.
> >   $ cd /sys/kernel/debug/apei/einj
> >   $ echo 0x00000040 > error_type
> >   $ echo 0x4 > flags
> >   $ echo 0x891000 > param4
> >
> >   # Root Error Status is initially clear
> >   $ setpci -s <Dev ID> ECAP0001+0x30.w
> >   0000
> >
> >   # Inject one error
> >   $ echo 1 > error_inject
> >
> >   # Interrupt received
> >   pcieport <Dev ID>: AER: Root Error Status 0001
> >
> >   # Inject another error (within 5 seconds)
> >   $ echo 1 > error_inject
> >
> >   # No interrupt received, but "multiple ERR_COR" is now set
> >   $ setpci -s <Dev ID> ECAP0001+0x30.w
> >   0003
> >
> >   # Wait for a while, then clear ERR_COR. A new interrupt immediately
> >     fires.
> >   $ setpci -s <Dev ID> ECAP0001+0x30.w=0x1
> >   pcieport <Dev ID>: AER: Root Error Status 0002
> >
> > Currently, the above issue has been only reproduced in the ICL server
> > platform.
> >
> > [Eric: proposed reproducing steps]
> Hmm, this differs from the procedure I described on v1, and I don't
> think will work as described here.

I have attempted to modify the steps to reproduce it without returning
IRQ_NONE for all cases (which will break the functionality). But I
think I did not correct the last few steps.

How about replacing the last 3 steps with following?

 # Inject another error (within 5 seconds)
 $ echo 1 > error_inject

 # You will get a new IRQ with only multiple ERR_COR bit set
 pcieport <Dev ID>: AER: Root Error Status 0002

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer