On Tue, Sep 26, 2000 at 11:04:12AM -0700, Jun Sun wrote:
> > > If we have to use "-mips2" option, is there a clean way which allows us
> > > to "uld/usw" instructions (instead of manually twicking the compilation
> > > for each file that uses them)?
> Ralf, before the perfect solution is found, the following patch makes
> the gcc complain go away. It just use ".set mips3" pragma.
It's still perfectly broken. Uld is a 64-bit instruction meaning you still
could get into problems with register corruption or even reserved instruction
exceptions on 32-bit cpus. Not too mention that nobody did notice that
the constraints of the inline assembler were broken for all access sizes
plus a cast that would have cut off the upper 32 bit of a 64 bit access in
any case. That's fixed now.
> I am pretty close to get USB running with the v2.4-test5. The unaligned
> access is the minor problem. The bigger problem I am fighting with now
> is bus_to_virt()/virt_to_bus() and USB interrupt.
The unaligned exception handler is fairly expensive. I suggest you should
try to get proper alignment and where that is not possible go through
the entire code and use get_unaligned. It's going to make a noticable
difference in performance.