Re: fix for shared interrupt in serial i/o

[Stefani Seibold]

Forget my last posting, the shared serial irq handler works fine. The 
state i had described will never happens.
So, the only good thing in this patch is the low_latency modification 
and the test of the ier shadow register in the receive_chars(), 
transmit_chars() and check_modem_status().
Sorry, next time i will think more about it, bevore posting it.
Greetings,
Stefani