Re: [PATCH v2 1/8] PCI/AER: Remove aer_print_port_info

[Bjorn Helgaas <helgaas@kernel.org>]

On Tue, Mar 04, 2025 at 05:04:21PM -0800, Jon Pan-Doh wrote:
> On Tue, Mar 4, 2025 at 10:32 AM Bjorn Helgaas <helgaas@kernel.org> wrote:
> > It's true this is redundant information, but that e1000e device may
> > no longer be accessible.
> >
> > In that case, I think aer_get_device_error_info() would probably
> > return 0 because config reads would all return ~0, and
> > PCI_ERR_COR_STATUS & ~PCI_ERR_COR_MASK would be 0, so
> > we probably wouldn't see the e1000e messages at all.
> 
> Wouldn't we have larger issues if the device is no longer accessible?
> Would a log suffice in that case (i.e. when aer_get_device_error()
> returns 0)? Something along the lines of "{device} is not accessible
> while processing (un)correctable error"

It's quite likely that a device is inaccessible after an uncorrectable
error.

DPC takes the link down automatically for uncorrectable errors, but I
don't think aer_print_port_info() is used in that case anyway.

Documentation/PCI/pci-error-recovery.rst mentions other cases where
the affected device is disconnected.

If the purpose of this patch is only to turn this:

  pcieport 0000:00:04.0: Correctable error message received from 0000:01:00.0
  e1000e 0000:01:00.0: PCIe Bus Error: severity=Correctable, type=Data Link
Layer, (Receiver ID)
  e1000e 0000:01:00.0:   device [8086:10d3] error status/mask=00000040/0000e000
  e1000e 0000:01:00.0:    [ 6] BadTLP

into this:

  e1000e 0000:01:00.0: PCIe Bus Error: severity=Correctable, type=Data Link
Layer, (Receiver ID)
  e1000e 0000:01:00.0:   device [8086:10d3] error status/mask=00000040/0000e000
  e1000e 0000:01:00.0:    [ 6] BadTLP

I don't think it's worth it.

I guess the problem is that future patches rate limit the e1000e
messages, and we really need to rate limit the pcieport message using
the same e1000e ratelimit_state.  We do know the Requester ID of the
device, so maybe we could look up that ratelimit_state?