Re: Is in_le32 and out_le32 atomic?

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 <><