8250: Fix oops from setserial
If you setserial a port which has never been initialised we change the type
but don't update the I/O method pointers. The same problem is true if you
change the io type of a port - but nobody ever does that so nobody noticed!
Remember the old type and when attaching if the type has changed reload the
port accessor pointers. We can't do it blindly as some 8250 drivers load custom
accessors and we must not stomp those.
Tested-by: Victor Seryodkin <vvscore@gmail.com>
Closes-bug: #13367
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index b4b3981..a0127e9 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -137,6 +137,7 @@
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 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 @@
p->serial_out = io_serial_out;
break;
}
+ /* Remember loaded iotype */
+ up->cur_iotype = p->iotype;
}
static void
@@ -1937,6 +1941,9 @@
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 @@
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 @@
{
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++) {