On 11/9/08 11:59, "Tian, Kevin" <kevin.tian@xxxxxxxxx> wrote:
>> Also, in your patch, you unmask LVTT after reprogramming the
>> LAPIC counter.
>> Isn't there a race where the LAPIC timer generates an
>> interrupt event before
>> you unmask the LVTT and hence you lose the interrupt (since I
>> assume the
>> LAPIC interrupt is basically an internal one-shot signal which
>> does not get
>> latched in any way)? So you'd probably need to reprogram_timer(0), then
>> enable the timer, then reprogram_timer(<actual value>).
>> 
>
> You're correct. It will be fixed.
Thanks. I'm not sure whether the reprogram_timer(0) before re-enabling is
really required. It looks like Linux doesn't do similar (although if course
it does re-programming after re-enabling to avoid the above race).
I suppose repogram_timer(0) is cheap so you might choose to do it anyway.
It's up to you...
 -- Keir
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