Re: [PATCH v4 0/10] CXL Reset support for Type 2 devices

[<dan.j.williams@intel.com>]

Alex Williamson wrote:
[..]
> Is it really appropriate to consider cxl_reset as just another PCI reset
> method given the scope difference?  Does there need to be a way to
> specify the scope when calling pci_reset_function() for drivers aware
> of CXL.mem/cache?

Right, FWIW, I am of the opinion that trying to plumb CXL reset through
PCI reset is an awkward fit that will be an ongoing source of pain. For
the same reason that CXL protocol error handling is designed to have
little do with PCIe protocol error handling, CXL is not PCIe. For
example, the goal in the error handling case is to arrive at a point
where the PCIe error handling implementation can continue to evolve
without inflicting the maintenance burden load of "what about CXL?".
Notifications are simply shunted over to the CXL core early in the flow.
CXL reset does not need any PCI core entanglements as far as I can see.

Once the protocol error handling series has landed there is a potential
to extend that with CXL Reset recovery. However, that needs a clear
error model defined as to which resets have a chance of recovering
*system* operation when CXL.cache/mem fails. In Terry's series, panic /
reboot is the recovery, not reset.