[U-Boot] [PATCH] arm: enable unaligned access on ARMv7

Måns Rullgård
2012-06-23T19:50:52Z

Albert ARIBAUD <albert.u.boot@aribaud.net> writes:

>> >> I cannot see how enabling a hardware feature can be seen as
>> >> allowing of lax behaviour. As some of the USB structs are used to
>> >> access hardware registers, we can not align every struct there.
>
> If the access is in true RAM, then we can always realign the data; and
> I don't know of memory-mapped registers which would be unaligned wrt
> their width. If some USB controller is designed so, then the fix should
> only and explicitly affect that controller, because we don't know it it
> will always be used with an ARM implementation that can do unaligned
> accesses.

The ARM architecture does not permit unaligned accesses to strongly
ordered or device memory, so MMIO register accesses are always aligned.

--
M?ns Rullg?rd
mans at mansr.com