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path: root/drivers/serial/8250.c
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Diffstat (limited to 'drivers/serial/8250.c')
-rw-r--r--drivers/serial/8250.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index b4b39811b44..a0127e93ade 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -137,6 +137,7 @@ struct uart_8250_port {
unsigned char mcr;
unsigned char mcr_mask; /* mask of user bits */
unsigned char mcr_force; /* mask of forced bits */
+ unsigned char cur_iotype; /* Running I/O type */
/*
* Some bits in registers are cleared on a read, so they must
@@ -471,6 +472,7 @@ static void io_serial_out(struct uart_port *p, int offset, int value)
static void set_io_from_upio(struct uart_port *p)
{
+ struct uart_8250_port *up = (struct uart_8250_port *)p;
switch (p->iotype) {
case UPIO_HUB6:
p->serial_in = hub6_serial_in;
@@ -509,6 +511,8 @@ static void set_io_from_upio(struct uart_port *p)
p->serial_out = io_serial_out;
break;
}
+ /* Remember loaded iotype */
+ up->cur_iotype = p->iotype;
}
static void
@@ -1937,6 +1941,9 @@ static int serial8250_startup(struct uart_port *port)
up->capabilities = uart_config[up->port.type].flags;
up->mcr = 0;
+ if (up->port.iotype != up->cur_iotype)
+ set_io_from_upio(port);
+
if (up->port.type == PORT_16C950) {
/* Wake up and initialize UART */
up->acr = 0;
@@ -2563,6 +2570,9 @@ static void serial8250_config_port(struct uart_port *port, int flags)
if (ret < 0)
probeflags &= ~PROBE_RSA;
+ if (up->port.iotype != up->cur_iotype)
+ set_io_from_upio(port);
+
if (flags & UART_CONFIG_TYPE)
autoconfig(up, probeflags);
if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
@@ -2671,6 +2681,11 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev)
{
int i;
+ for (i = 0; i < nr_uarts; i++) {
+ struct uart_8250_port *up = &serial8250_ports[i];
+ up->cur_iotype = 0xFF;
+ }
+
serial8250_isa_init_ports();
for (i = 0; i < nr_uarts; i++) {