Re: [ACPI] Re: Linux 2.4.26-rc1 (cmpxchg vs 80386 build)

[Maciej W. Rozycki]

On Thu, 1 Apr 2004, Len Brown wrote:

> ACPI specifies a location in regular memory that is used to contain the
> lock.  The lock is used both by the CPU and by the embedded controller
> to cover access to shared registers.  We don't spin on this lock because
> we don't know how long the embedded controller might hold it.  Instead
> when we fail to acquire it we schedule an event to trigger when the lock
> is free.

 OK, that's clear to me now.  Then does this lock really require
"cmpxchg"?  Wouldn't a lone "xchg" suffice?

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@xxxxxxxxxxxxx, PGP key available        +
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