From: David S. Miller <[email protected]>
Subject: [2.6.22.2 review 05/84] [PATCH] [SERIAL]: Fix console write locking in sparc drivers.
Mirror the logic in 8250 for proper console write locking
when SYSRQ is triggered or an OOPS is in progress.
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/serial/sunhv.c | 30 ++++++++++++++++++++++++++----
drivers/serial/sunsab.c | 19 ++++++++++++++-----
drivers/serial/sunsu.c | 14 ++++++++++++++
drivers/serial/sunzilog.c | 17 ++++++++++++++---
4 files changed, 68 insertions(+), 12 deletions(-)
--- a/drivers/serial/sunhv.c
+++ b/drivers/serial/sunhv.c
@@ -440,8 +440,16 @@ static void sunhv_console_write_paged(st
{
struct uart_port *port = sunhv_port;
unsigned long flags;
+ int locked = 1;
+
+ local_irq_save(flags);
+ if (port->sysrq) {
+ locked = 0;
+ } else if (oops_in_progress) {
+ locked = spin_trylock(&port->lock);
+ } else
+ spin_lock(&port->lock);
- spin_lock_irqsave(&port->lock, flags);
while (n > 0) {
unsigned long ra = __pa(con_write_page);
unsigned long page_bytes;
@@ -469,7 +477,10 @@ static void sunhv_console_write_paged(st
ra += written;
}
}
- spin_unlock_irqrestore(&port->lock, flags);
+
+ if (locked)
+ spin_unlock(&port->lock);
+ local_irq_restore(flags);
}
static inline void sunhv_console_putchar(struct uart_port *port, char c)
@@ -488,7 +499,15 @@ static void sunhv_console_write_bychar(s
{
struct uart_port *port = sunhv_port;
unsigned long flags;
- int i;
+ int i, locked = 1;
+
+ local_irq_save(flags);
+ if (port->sysrq) {
+ locked = 0;
+ } else if (oops_in_progress) {
+ locked = spin_trylock(&port->lock);
+ } else
+ spin_lock(&port->lock);
spin_lock_irqsave(&port->lock, flags);
for (i = 0; i < n; i++) {
@@ -496,7 +515,10 @@ static void sunhv_console_write_bychar(s
sunhv_console_putchar(port, '\r');
sunhv_console_putchar(port, *s++);
}
- spin_unlock_irqrestore(&port->lock, flags);
+
+ if (locked)
+ spin_unlock(&port->lock);
+ local_irq_restore(flags);
}
static struct console sunhv_console = {
--- a/drivers/serial/sunsab.c
+++ b/drivers/serial/sunsab.c
@@ -860,22 +860,31 @@ static int num_channels;
static void sunsab_console_putchar(struct uart_port *port, int c)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *)port;
- unsigned long flags;
-
- spin_lock_irqsave(&up->port.lock, flags);
sunsab_tec_wait(up);
writeb(c, &up->regs->w.tic);
-
- spin_unlock_irqrestore(&up->port.lock, flags);
}
static void sunsab_console_write(struct console *con, const char *s, unsigned n)
{
struct uart_sunsab_port *up = &sunsab_ports[con->index];
+ unsigned long flags;
+ int locked = 1;
+
+ local_irq_save(flags);
+ if (up->port.sysrq) {
+ locked = 0;
+ } else if (oops_in_progress) {
+ locked = spin_trylock(&up->port.lock);
+ } else
+ spin_lock(&up->port.lock);
uart_console_write(&up->port, s, n, sunsab_console_putchar);
sunsab_tec_wait(up);
+
+ if (locked)
+ spin_unlock(&up->port.lock);
+ local_irq_restore(flags);
}
static int sunsab_console_setup(struct console *con, char *options)
--- a/drivers/serial/sunsu.c
+++ b/drivers/serial/sunsu.c
@@ -1288,7 +1288,17 @@ static void sunsu_console_write(struct c
unsigned int count)
{
struct uart_sunsu_port *up = &sunsu_ports[co->index];
+ unsigned long flags;
unsigned int ier;
+ int locked = 1;
+
+ local_irq_save(flags);
+ if (up->port.sysrq) {
+ locked = 0;
+ } else if (oops_in_progress) {
+ locked = spin_trylock(&up->port.lock);
+ } else
+ spin_lock(&up->port.lock);
/*
* First save the UER then disable the interrupts
@@ -1304,6 +1314,10 @@ static void sunsu_console_write(struct c
*/
wait_for_xmitr(up);
serial_out(up, UART_IER, ier);
+
+ if (locked)
+ spin_unlock(&up->port.lock);
+ local_irq_restore(flags);
}
/*
--- a/drivers/serial/sunzilog.c
+++ b/drivers/serial/sunzilog.c
@@ -9,7 +9,7 @@
* C. Dost, Pete Zaitcev, Ted Ts'o and Alex Buell for their
* work there.
*
- * Copyright (C) 2002, 2006 David S. Miller ([email protected])
+ * Copyright (C) 2002, 2006, 2007 David S. Miller ([email protected])
*/
#include <linux/module.h>
@@ -1151,11 +1151,22 @@ sunzilog_console_write(struct console *c
{
struct uart_sunzilog_port *up = &sunzilog_port_table[con->index];
unsigned long flags;
+ int locked = 1;
+
+ local_irq_save(flags);
+ if (up->port.sysrq) {
+ locked = 0;
+ } else if (oops_in_progress) {
+ locked = spin_trylock(&up->port.lock);
+ } else
+ spin_lock(&up->port.lock);
- spin_lock_irqsave(&up->port.lock, flags);
uart_console_write(&up->port, s, count, sunzilog_putchar);
udelay(2);
- spin_unlock_irqrestore(&up->port.lock, flags);
+
+ if (locked)
+ spin_unlock(&up->port.lock);
+ local_irq_restore(flags);
}
static int __init sunzilog_console_setup(struct console *con, char *options)
--
-
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