[PATCH] i8xx_tco.c: arm watchdog only when started
i8xx_tco.c v0.08: only "arm" the watchdog when the watchdog has been
started. (Kernel Bug 4251: system reset when battery is read and i8xx_tco
driver loaded)
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/char/watchdog/i8xx_tco.c b/drivers/char/watchdog/i8xx_tco.c
index f975dab..a13395e 100644
--- a/drivers/char/watchdog/i8xx_tco.c
+++ b/drivers/char/watchdog/i8xx_tco.c
@@ -1,5 +1,5 @@
/*
- * i8xx_tco 0.07: TCO timer driver for i8xx chipsets
+ * i8xx_tco: TCO timer driver for i8xx chipsets
*
* (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights Reserved.
* http://www.kernelconcepts.de
@@ -63,6 +63,9 @@
* 20050128 Wim Van Sebroeck <wim@iguana.be>
* 0.07 Added support for the ICH4-M, ICH6, ICH6R, ICH6-M, ICH6W and ICH6RW
* chipsets. Also added support for the "undocumented" ICH7 chipset.
+ * 20050807 Wim Van Sebroeck <wim@iguana.be>
+ * 0.08 Make sure that the watchdog is only "armed" when started.
+ * (Kernel Bug 4251)
*/
/*
@@ -87,7 +90,7 @@
#include "i8xx_tco.h"
/* Module and version information */
-#define TCO_VERSION "0.07"
+#define TCO_VERSION "0.08"
#define TCO_MODULE_NAME "i8xx TCO timer"
#define TCO_DRIVER_NAME TCO_MODULE_NAME ", v" TCO_VERSION
#define PFX TCO_MODULE_NAME ": "
@@ -125,10 +128,18 @@
unsigned char val;
spin_lock(&tco_lock);
+
+ /* disable chipset's NO_REBOOT bit */
+ pci_read_config_byte (i8xx_tco_pci, 0xd4, &val);
+ val &= 0xfd;
+ pci_write_config_byte (i8xx_tco_pci, 0xd4, val);
+
+ /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
val = inb (TCO1_CNT + 1);
val &= 0xf7;
outb (val, TCO1_CNT + 1);
val = inb (TCO1_CNT + 1);
+
spin_unlock(&tco_lock);
if (val & 0x08)
@@ -138,13 +149,20 @@
static int tco_timer_stop (void)
{
- unsigned char val;
+ unsigned char val, val1;
spin_lock(&tco_lock);
+ /* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
val = inb (TCO1_CNT + 1);
val |= 0x08;
outb (val, TCO1_CNT + 1);
val = inb (TCO1_CNT + 1);
+
+ /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
+ pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
+ val1 |= 0x02;
+ pci_write_config_byte (i8xx_tco_pci, 0xd4, val1);
+
spin_unlock(&tco_lock);
if ((val & 0x08) == 0)
@@ -155,6 +173,7 @@
static int tco_timer_keepalive (void)
{
spin_lock(&tco_lock);
+ /* Reload the timer by writing to the TCO Timer Reload register */
outb (0x01, TCO1_RLD);
spin_unlock(&tco_lock);
return 0;
@@ -417,9 +436,8 @@
printk (KERN_ERR PFX "failed to get TCOBASE address\n");
return 0;
}
- /*
- * Check chipset's NO_REBOOT bit
- */
+
+ /* Check chipset's NO_REBOOT bit */
pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
if (val1 & 0x02) {
val1 &= 0xfd;
@@ -430,6 +448,10 @@
return 0; /* Cannot reset NO_REBOOT bit */
}
}
+ /* Disable reboots untill the watchdog starts */
+ val1 |= 0x02;
+ pci_write_config_byte (i8xx_tco_pci, 0xd4, val1);
+
/* Set the TCO_EN bit in SMI_EN register */
if (!request_region (SMI_EN + 1, 1, "i8xx TCO")) {
printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
@@ -505,17 +527,10 @@
static void __exit watchdog_cleanup (void)
{
- u8 val;
-
/* Stop the timer before we leave */
if (!nowayout)
tco_timer_stop ();
- /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
- pci_read_config_byte (i8xx_tco_pci, 0xd4, &val);
- val |= 0x02;
- pci_write_config_byte (i8xx_tco_pci, 0xd4, val);
-
/* Deregister */
misc_deregister (&i8xx_tco_miscdev);
unregister_reboot_notifier(&i8xx_tco_notifier);