Messages in this thread | | | Date | Mon, 20 Jun 2011 17:05:20 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [PATCH] USB: ehci: use packed,aligned(4) instead of removing the packed attribute |
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On Mon, 20 Jun 2011, Arnd Bergmann wrote:
> On Monday 20 June 2011 20:39:02 Alan Stern wrote: > > 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? > > No. When the structure is marked packed, it's broken because it relies > on undefined behavior. If it's not packed, there is no problem. > > > > 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? > > Only on compilers that are not able to build Linux kernels anyway.
Just as I thought. There's no reason to accept the proposed patch; we're fine the way we are now.
Alan Stern
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