On Mon, 20 Jun 2011, Alexander Holler wrote:

I see it that way: packed is needed to be sure that at least for struct 
ehci_regs there are no padding bytes inbetween the members.

But is it _really_ needed?

It might 
work without, but that depends on the compiler (-version, architecture, 
whatever).

Have there _ever_ been _any_ combinations of compiler, version, 
architecture, whatever, that had unwanted padding bytes in this 
structure?

Alan Stern