The problem is not gcc4 but the code itself. The BD_STATUS() macro can't
be used for busy-waiting since it strips the 'volatile' property from
the bd variable. gcc3 was working by pure luck.
This is a follow on patch to "Fix the UEC driver bug of QE"
The patch prevents the GCC tool chain from striping useful code for
optimization. It will make UEC ethernet driver workable, Otherwise the
UEC will fail in tx when you are using gcc4.x. but the driver can work
when using gcc3.4.3.
CHANGELOG
*Prevent the GCC from striping code for optimization, Otherwise the UEC
will tx failed when you are using gcc4.x.
Signed-off-by: Dave Liu <daveliu@freescale.com>