RE: [EXT] Re: [net PATCH V2 1/4] octeontx2-pf: Update PFC configuration

[Suman Ghosh]

>Thanks for replying a week late, always a good use of maintainers time
>to swap back all the context from random conversations!
[Suman] Sorry for being late this time Jakub. I will remove this patch from the patch set and will push a new version with the other three patches. I will analyze the issue in more detail and will produce a proper fix.
>
>On Fri, 18 Aug 2023 06:54:52 +0000 Suman Ghosh wrote:
>> >If there is any error in open() this will silently take the interface
>> >down. Can't you force a NAPI poll or some such, if the concern is a
>> >missed IRQ?
>> [Suman] I can check the return type of open() and report in case of
>> error. But even if we force NAPI poll we might not be able to control
>> the watchdog reset. If we have a running traffic and interface is up,
>> when we force NAPI poll, then the new packets will have updated
>> scheduler queue and we will still loose the completion interrupts of
>> the previous packets.
>
>Why does it matter that you lost an interrupt if the poll has happened.
>Can you describe the problem in more detail?
>
>> Do you see any issue if I handle the error situation during open()
>call?
>
>No, for years we have been rejecting code which does this.
>If the machine is under memory pressure allocating all the buffers for
>rings can easily fail and make the machine drop off the network.
>You either have to refuse to change this setting at runtime or implement
>prepare/commit reconfiguration model like other modern drivers, where
>allocations are done before the stop().