RE: [PATCH net-next v2 6/6] net: qualcomm: rmnet: don't use C bit-fields in rmnet checksum header

[David Laight]

...
> Sort of related, I have been meaning to eliminate the
> pointless __aligned(1) tags on rmnet structures defined
> in <linux/if_rmnet.h>.  It wouldn't hurt to use __packed,
> though I think they're all 4 or 8 bytes naturally anyway.
> Perhaps marking them __aligned(4) would help identify
> potential unaligned accesses?

Don't use __packed (etc) unless the data might be misaligned.
If the architecture doesn't support misaligned memory
accesses then the compiler has to generate code that
does byte accesses and shifts.

__aligned(4) is mostly useful for structures that have
to have an 8-byte field on a 4-byte boundary.
(As happens in the x86 compat32 code.)

	David

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