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authorWim Van Sebroeck <wim@iguana.be>2006-09-02 12:50:20 -0400
committerWim Van Sebroeck <wim@iguana.be>2006-10-04 16:41:48 -0400
commitab9d441425559aa035ba6327f21e8922e8a13927 (patch)
treee1deeab38550be809d50e804a669dbd8ff2992f5 /drivers/char/watchdog/w83627hf_wdt.c
parente0845bf4e1df07e16fa39d96508a1ba4a480ce3e (diff)
[WATCHDOG] w836?7hf_wdt spinlock fixes.
Add io spinlocks to prevent possible race conditions between start and stop operations that are issued from different child processes where the master process opened /dev/watchdog. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/char/watchdog/w83627hf_wdt.c')
-rw-r--r--drivers/char/watchdog/w83627hf_wdt.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/char/watchdog/w83627hf_wdt.c b/drivers/char/watchdog/w83627hf_wdt.c
index b4adc527e687..07d4bff27226 100644
--- a/drivers/char/watchdog/w83627hf_wdt.c
+++ b/drivers/char/watchdog/w83627hf_wdt.c
@@ -33,6 +33,7 @@
33#include <linux/notifier.h> 33#include <linux/notifier.h>
34#include <linux/reboot.h> 34#include <linux/reboot.h>
35#include <linux/init.h> 35#include <linux/init.h>
36#include <linux/spinlock.h>
36 37
37#include <asm/io.h> 38#include <asm/io.h>
38#include <asm/uaccess.h> 39#include <asm/uaccess.h>
@@ -44,6 +45,7 @@
44 45
45static unsigned long wdt_is_open; 46static unsigned long wdt_is_open;
46static char expect_close; 47static char expect_close;
48static spinlock_t io_lock;
47 49
48/* You must set this - there is no sane way to probe for this board. */ 50/* You must set this - there is no sane way to probe for this board. */
49static int wdt_io = 0x2E; 51static int wdt_io = 0x2E;
@@ -110,12 +112,16 @@ w83627hf_init(void)
110static void 112static void
111wdt_ctrl(int timeout) 113wdt_ctrl(int timeout)
112{ 114{
115 spin_lock(&io_lock);
116
113 w83627hf_select_wd_register(); 117 w83627hf_select_wd_register();
114 118
115 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 119 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
116 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */ 120 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
117 121
118 w83627hf_unselect_wd_register(); 122 w83627hf_unselect_wd_register();
123
124 spin_unlock(&io_lock);
119} 125}
120 126
121static int 127static int
@@ -303,6 +309,8 @@ wdt_init(void)
303{ 309{
304 int ret; 310 int ret;
305 311
312 spin_lock_init(&io_lock);
313
306 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF Super I/O chip initialising.\n"); 314 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF Super I/O chip initialising.\n");
307 315
308 if (wdt_set_heartbeat(timeout)) { 316 if (wdt_set_heartbeat(timeout)) {