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authorAlan Cox <alan@linux.intel.com>2009-05-28 14:01:35 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2009-05-29 08:42:38 -0700
commitb8e7e40abeac49644fec4a4f52ffe74c7b05eca0 (patch)
tree56a73537ec1111098f785ef26e4aa7a2e6bdd1f2 /drivers/serial
parent715fe7af9fd7328af661742bfadc195e665a837f (diff)
downloadop-kernel-dev-b8e7e40abeac49644fec4a4f52ffe74c7b05eca0.zip
op-kernel-dev-b8e7e40abeac49644fec4a4f52ffe74c7b05eca0.tar.gz
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>
Diffstat (limited to 'drivers/serial')
-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 b4b3981..a0127e9 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++) {
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