Re: [PATCH] USB: ehci: use packed,aligned(4) instead of removing the packed attribute

From: Nicolas Pitre
Date: Mon Jun 20 2011 - 17:03:25 EST


On Mon, 20 Jun 2011, Arnd Bergmann wrote:

> On Monday 20 June 2011 22:28:49 Nicolas Pitre wrote:
> > On Mon, 20 Jun 2011, Arnd Bergmann wrote:
> >
> > > On Monday 20 June 2011 19:39:34 Alexander Holler wrote:
> > > > That packed without an additional aligned() caused errors on ARM with
> > > > gcc 4.6 is another problem which got (currently) fixed by removing packed.
> > >
> > > Packed caused errors because it is *wrong*. The code as it was used undefined
> > > behavior in the language.
> >
> > I wouldn't call this issue as such, but this is a Red herring.
> >
> > Could you please provide a pointer to the structure definition so a
> > second opinion to the usefulness of __packed there could be provided?
>
> The structures in question are ehci_caps, ehci_regs and ehci_dbg_port.

OK. If anyone was still entertaining any doubts, those structures do
not require any packed attribute what so ever.

> The patch that remove the __packed attribute was 139540170 "USB: ehci:
> remove structure packing from ehci_def".

Too late for this, but for the record:

Reviewed-by: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>

Hopefully this thread still gathered enough wisdom about proper usage of
the packed and aligned attributes into the list archive.


Nicolas
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