Re: [PATCH v19 02/14] cxl/ras: Fix cxl_rch_get_aer_severity() wrong severity register

[Terry Bowman]

On 9/3/26 03:35, Lukas Wunner wrote:
> Hi Terry,
>
> You've submitted v20 of this series, but the following
> questions haven't been addressed yet AFAICS.  I'd be
> grateful if you could take a look:
>
> On Sun, Aug 09, 2026 at 05:57:23PM +0200, Lukas Wunner wrote:
> > Am I missing something?  Is a scenario ever conceivable where the RCEC
> > receives a message with different severity than what is inferred from
> > the registers by cxl_rch_get_aer_severity()?
> [...]
> > These so-called Advisory Non-Fatal Errors set one bit in the Correctable
> > Error Status Register (Advisory Non-Fatal Error Status, bit 13) and
> > additionally one or more bits in the Uncorrectable Error Status Register
> > (see the commit for details).
> >
> > cxl_rch_get_aer_severity() is not able to cope with such errors and
> > will incorrectly infer that the severity is AER_NONFATAL.
> >
> > Now I *think* this is not a problem because Advisory Non-Fatal Errors
> > are masked by default and the commit only unmasks them on regular PCI
> > devices, not in the RCRB of a CXL device.  Only once bit 13 in the
> > Correctable Error Mask Register is cleared in the RCRB will
> > cxl_rch_get_aer_severity() fail.  Right?
>
> Thanks,
>
> Lukas

Hi Lukas,

I’m sorry for missing your August 9 reply. Also, I am currently on PTO 
this week and don’t have my work laptop, so I am responding from my 
personal email account. I’ll be back in the office Wednesday.

Thanks for pointing out the issue with CE and UCE errors reported
simultaneously. I agree this is a problem and have addressed it in v20.

In v20 I remove the unused `cxl_rch_get_aer_severity()` helper, take a
snapshot of the AER registers before calling `pci_print_aer()`, and now
handle the CE and UCE parts in separate blocks. The UCE status is logged
unconditionally, which prevents a fatal record from being lost under the
advisory‑non‑fatal path. These changes directly address the scenario you
raised for v19 and also cover any other situation where a CE and a UCE
are co‑logged. The patch ishere: <https://lkml.org/lkml/2026/9/2/1629>
(v20 3/9).

Please let me know if you see any remaining concerns or corner cases
that are not yet covered. Thanks again for your review and for pointing
out the issue.

- Terry