[PATCH v4 27/32] cxlflash: Fix to prevent stale AFU RRQ

Daniel Axtens dja at axtens.net
Thu Oct 1 09:51:22 AEST 2015


>>> Following an adapter reset, the AFU RRQ that resides in host memory
>>> holds stale data. This can lead to a condition where the RRQ interrupt
>>> handler tries to process stale entries and/or endlessly loops due to an
>>> out of sync generation bit.
>>> 
>>> To fix, the AFU RRQ in host memory needs to be cleared after each reset.
>> 
>> This looks good. Do you need anything to bail out of cxlflash_rrq_irq if
>> the data goes stale or to all Fs while that function is running?
>
> We're not performing an MMIO here, so I'm not sure how the all Fs check
> would apply. We're also protected fairly well by the generation bit. I suppose
> we could look at adding some type of 'max iterations' count to protect against
> a runaway handler but that would be in a future patch.

Ah, right you are. I had confused all Fs with UEs.

Reviewed-by: Daniel Axtens <dja at axtens.net>

Regards,
Daniel



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