From: Jean Tourrilhes The following command will do nothing at all on 2.5.X : setserial /dev/ttyS0 uart none drivers/serial/core.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletion(-) diff -puN drivers/serial/core.c~setserial-fix drivers/serial/core.c --- 25/drivers/serial/core.c~setserial-fix 2003-04-16 18:30:13.000000000 -0700 +++ 25-akpm/drivers/serial/core.c 2003-04-16 18:30:13.000000000 -0700 @@ -782,8 +782,12 @@ uart_set_info(struct uart_state *state, /* * Claim and map the new regions */ - if (port->type != PORT_UNKNOWN) + if (port->type != PORT_UNKNOWN) { retval = port->ops->request_port(port); + } else { + /* Always success - Jean II */ + retval = 0; + } /* * If we fail to request resources for the _