On Thu, 6 Jul 2006 13:08:49 +0400
Paul Drynoff <pauldrynoff@xxxxxxxxx> wrote:
> I tried 2.6.17-mm6, and got durring boot:
> fb0: VGA16 VGA frame buffer device
> BUG: spinlock bad magic on CPU#0, swapper/1
> _raw_spin_lock
> _spin_lock_irqsave
> __down
> __down_faied
> .text.lock.cm_sbs
> acpi_ac_init
> init
> kernel_thread_helper
Thanks. This'll probably help.
From: Andrew Morton <akpm@xxxxxxxx>
cm_sbs_sem is being downed (via acpi_ac_init->acpi_lock_ac_dir) before it is
initialised, with grave results.
- Make it a mutex
- Initialise it
- Make it static
- Clean other stuff up.
Cc: "Brown, Len" <len.brown@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/acpi/cm_sbs.c | 46 ++++++++++++----------------------------
1 file changed, 14 insertions(+), 32 deletions(-)
diff -puN drivers/acpi/cm_sbs.c~acpi-initialise-cm_sbs_sem drivers/acpi/cm_sbs.c
--- a/drivers/acpi/cm_sbs.c~acpi-initialise-cm_sbs_sem
+++ a/drivers/acpi/cm_sbs.c
@@ -39,50 +39,43 @@ ACPI_MODULE_NAME("cm_sbs")
static struct proc_dir_entry *acpi_ac_dir;
static struct proc_dir_entry *acpi_battery_dir;
-static struct semaphore cm_sbs_sem;
+static DEFINE_MUTEX(cm_sbs_mutex);
-static int lock_ac_dir_cnt = 0;
-static int lock_battery_dir_cnt = 0;
+static int lock_ac_dir_cnt;
+static int lock_battery_dir_cnt;
struct proc_dir_entry *acpi_lock_ac_dir(void)
{
-
- down(&cm_sbs_sem);
- if (!acpi_ac_dir) {
+ mutex_lock(&cm_sbs_mutex);
+ if (!acpi_ac_dir)
acpi_ac_dir = proc_mkdir(ACPI_AC_CLASS, acpi_root_dir);
- }
if (acpi_ac_dir) {
lock_ac_dir_cnt++;
} else {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
"Cannot create %s\n", ACPI_AC_CLASS));
}
- up(&cm_sbs_sem);
+ mutex_unlock(&cm_sbs_mutex);
return acpi_ac_dir;
}
-
EXPORT_SYMBOL(acpi_lock_ac_dir);
void acpi_unlock_ac_dir(struct proc_dir_entry *acpi_ac_dir_param)
{
-
- down(&cm_sbs_sem);
- if (acpi_ac_dir_param) {
+ mutex_lock(&cm_sbs_mutex);
+ if (acpi_ac_dir_param)
lock_ac_dir_cnt--;
- }
if (lock_ac_dir_cnt == 0 && acpi_ac_dir_param && acpi_ac_dir) {
remove_proc_entry(ACPI_AC_CLASS, acpi_root_dir);
acpi_ac_dir = 0;
}
- up(&cm_sbs_sem);
+ mutex_unlock(&cm_sbs_mutex);
}
-
EXPORT_SYMBOL(acpi_unlock_ac_dir);
struct proc_dir_entry *acpi_lock_battery_dir(void)
{
-
- down(&cm_sbs_sem);
+ mutex_lock(&cm_sbs_mutex);
if (!acpi_battery_dir) {
acpi_battery_dir =
proc_mkdir(ACPI_BATTERY_CLASS, acpi_root_dir);
@@ -93,39 +86,28 @@ struct proc_dir_entry *acpi_lock_battery
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
"Cannot create %s\n", ACPI_BATTERY_CLASS));
}
- up(&cm_sbs_sem);
+ mutex_unlock(&cm_sbs_mutex);
return acpi_battery_dir;
}
-
EXPORT_SYMBOL(acpi_lock_battery_dir);
void acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir_param)
{
-
- down(&cm_sbs_sem);
- if (acpi_battery_dir_param) {
+ mutex_lock(&cm_sbs_mutex);
+ if (acpi_battery_dir_param)
lock_battery_dir_cnt--;
- }
if (lock_battery_dir_cnt == 0 && acpi_battery_dir_param
&& acpi_battery_dir) {
remove_proc_entry(ACPI_BATTERY_CLASS, acpi_root_dir);
acpi_battery_dir = 0;
}
- up(&cm_sbs_sem);
+ mutex_unlock(&cm_sbs_mutex);
return;
}
-
EXPORT_SYMBOL(acpi_unlock_battery_dir);
static int __init acpi_cm_sbs_init(void)
{
-
- if (acpi_disabled)
- return 0;
-
- init_MUTEX(&cm_sbs_sem);
-
return 0;
}
-
subsys_initcall(acpi_cm_sbs_init);
_
-
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
