Re: [PATCH 45/79] [PATCH] fix apic acking of irqs

[Maciej W. Rozycki]

On Wed, 19 Mar 2008, Glauber de Oliveira Costa wrote:

> EOI is a write-only register. Using write around will have the effect
> of reading it, which will make all subsequent reads of the ESR register
> to return an error code. It was unnotices for quite a while because main sources
> of reading the ESR register where done prior to apic interrupt enabling.

 Are you sure this actually triggers for APIC chips affected by the 
erratum in question?  And please note that for them the effect of two 
consecutive writes will be much more disastrous than setting a bit in the 
ESR register.

  Maciej
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