On Thu, Aug 1, 2013 at 2:10 PM, David Miller [off-list ref] wrote:

From: Russell King - ARM Linux <redacted>
Date: Thu, 1 Aug 2013 22:06:18 +0100

quoted

On Thu, Aug 01, 2013 at 02:04:47PM -0700, Joe Perches wrote:

quoted

On Thu, 2013-08-01 at 21:58 +0100, Russell King - ARM Linux wrote:

quoted

This seems rather obscure - I mean, it's not obvious to driver authors
that should be the case.  Would it not be better to make this a little
more obvious somehow?  Maybe __aligned(2) against mac_addr?  Or
maybe have a debugging check for it?

That'd be for David Miller (cc'd).

I believe he's argued in the past that any alignment check
for mac addresses was unnecessary.

For all I know it really might not matter because pasemi
can successfully dereference a ushort against an odd char
pointer.

I just noticed it and thought it'd be better moved.

As can ARM too for years now - either in hardware or via fixup for
kernel code.

But probably not a good idea if it's done in a fast path.

This particular driver is for the PA Semi chips, and I very much doubt
that compatible hardware will ever show up anywhere else; they're
fairly dependent on the I/O architecture of the chip and Apple has not
brought those aspects forward in their ARM chips, as far as I know.

So, you might as well leave the code alone for now. It's not used on
fast path, and the system definitely handles unaligned accesses for
this -- it has for years already.


-Olof