On Friday 08 December 2006 21:05, Wolfgang Grandegger wrote:
> Can anybody tell me why the spin_* protection is needed? I thought that
> 32-bit read and write operations are atomic.
>
The spinlocks are needed to guarantee ordering between the completion of
the i/o access and other code. A typical problem is that a store is
still on its way to the I/O device while the CPU has already left the
function that initiated it, and might call code that relies on the
value having arrived there.
Arnd <><
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