RE: mdelay causes BUG, please use udelay

[Feldman, Scott]

>   We probably shouldn't be doing this, but we can at least 
> avoid the BUG caused by doing an mdelay in interrupt context 
> if we change to udelay.

That's BUG is my fault.  I put that in there so no one would tempted to call
msec_delay in the interrupt context.  As you've discovered, I missed one
case where msec_delay is called in interrupt context: tx_timeout.  Dangit!

> -    msec_delay(10);
> +    usec_delay(10000);

Jeff, 10000 seems on the border of what's OK.  If it's acceptable, then
let's go for that.  Otherwise, we're going to have to chain several
mod_timer callbacks together to do a controller reset.

-scott