On Sun, Mar 02, 2025 at 07:43:41PM -0800, Sathyanarayanan Kuppuswamy wrote:

On 2/16/25 6:42 PM, Shuai Xue wrote:

quoted

The AER driver has historically avoided reading the configuration space of
an endpoint or RCiEP that reported a fatal error, considering the link to
that device unreliable. Consequently, when a fatal error occurs, the AER
and DPC drivers do not report specific error types, resulting in logs like:

   pcieport 0000:30:03.0: EDR: EDR event received
   pcieport 0000:30:03.0: DPC: containment event, status:0x0005 source:0x3400
   pcieport 0000:30:03.0: DPC: ERR_FATAL detected
   pcieport 0000:30:03.0: AER: broadcast error_detected message
   nvme nvme0: frozen state error detected, reset controller
   nvme 0000:34:00.0: ready 0ms after DPC
   pcieport 0000:30:03.0: AER: broadcast slot_reset message

AER status registers are sticky and Write-1-to-clear. If the link recovered
after hot reset, we can still safely access AER status of the error device.
In such case, report fatal errors which helps to figure out the error root
case.

After this patch, the logs like:

   pcieport 0000:30:03.0: EDR: EDR event received
   pcieport 0000:30:03.0: DPC: containment event, status:0x0005 source:0x3400
   pcieport 0000:30:03.0: DPC: ERR_FATAL detected
   pcieport 0000:30:03.0: AER: broadcast error_detected message
   nvme nvme0: frozen state error detected, reset controller
   pcieport 0000:30:03.0: waiting 100 ms for downstream link, after activation
   nvme 0000:34:00.0: ready 0ms after DPC
   nvme 0000:34:00.0: PCIe Bus Error: severity=Uncorrectable (Fatal), type=Data Link Layer, (Receiver ID)
   nvme 0000:34:00.0:   device [144d:a804] error status/mask=00000010/00504000
   nvme 0000:34:00.0:    [ 4] DLP                    (First)
   pcieport 0000:30:03.0: AER: broadcast slot_reset message

IMO, above info about device error details is more of a debug info. Since
the
main use of this info use to understand more details about the recovered
DPC error. So I think is better to print with debug tag. Lets see what
others
think.

My two cents: All AER logs are mostly error messages, so I don't see why this
one should be a debug message. But having said that, this new error log may
confuse users as if a new AER error is received post recovery. So adding
something that specifies that this belong to the previous AER error would be
good IMO.

- Mani

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