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acpi_pad: fix error checks 

There are some fixes listed below:
1. When met a bogus BIOS, the return value of cpu number maybe is
   a negative value so that acpi_pad_pur get an unexpected result.
2. the return value of function acpi_pad_idle_cpus is useless.
3. enhance the process of create_power_saving_task/destroy_power_saving_task
4. Add more error checks when evaluating _PUR object.
5. one typo fix

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Chen Gong 2009-12-14 09:42:28 +08:00 committed by Len Brown
parent 22763c5cf3
commit 3b8cb427e9
1 changed files with 20 additions and 17 deletions
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37
drivers/acpi/acpi_pad.c
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@ -207,7 +207,7 @@ static int power_saving_thread(void *data)
* the mechanism only works when all CPUs have RT task running,
* as if one CPU hasn't RT task, RT task from other CPUs will
* borrow CPU time from this CPU and cause RT task use > 95%
* CPU time. To make 'avoid staration' work, takes a nap here.
* CPU time. To make 'avoid starvation' work, takes a nap here.
*/
if (do_sleep)
schedule_timeout_killable(HZ * idle_pct / 100);
@ -221,14 +221,18 @@ static struct task_struct *ps_tsks[NR_CPUS];
static unsigned int ps_tsk_num;
static int create_power_saving_task(void)
{
int rc = -ENOMEM;
ps_tsks[ps_tsk_num] = kthread_run(power_saving_thread,
(void *)(unsigned long)ps_tsk_num,
"power_saving/%d", ps_tsk_num);
if (ps_tsks[ps_tsk_num]) {
rc = IS_ERR(ps_tsks[ps_tsk_num]) ? PTR_ERR(ps_tsks[ps_tsk_num]) : 0;
if (!rc)
ps_tsk_num++;
return 0;
}
return -EINVAL;
else
ps_tsks[ps_tsk_num] = NULL;
return rc;
}
static void destroy_power_saving_task(void)
@ -236,6 +240,7 @@ static void destroy_power_saving_task(void)
if (ps_tsk_num > 0) {
ps_tsk_num--;
kthread_stop(ps_tsks[ps_tsk_num]);
ps_tsks[ps_tsk_num] = NULL;
}
}
@ -252,7 +257,7 @@ static void set_power_saving_task_num(unsigned int num)
}
}
static int acpi_pad_idle_cpus(unsigned int num_cpus)
static void acpi_pad_idle_cpus(unsigned int num_cpus)
{
get_online_cpus();
@ -260,7 +265,6 @@ static int acpi_pad_idle_cpus(unsigned int num_cpus)
set_power_saving_task_num(num_cpus);
put_online_cpus();
return 0;
}
static uint32_t acpi_pad_idle_cpus_num(void)
@ -368,19 +372,21 @@ static void acpi_pad_remove_sysfs(struct acpi_device *device)
static int acpi_pad_pur(acpi_handle handle, int *num_cpus)
{
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_status status;
union acpi_object *package;
int rev, num, ret = -EINVAL;
status = acpi_evaluate_object(handle, "_PUR", NULL, &buffer);
if (ACPI_FAILURE(status))
if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer)))
return -EINVAL;
if (!buffer.length || !buffer.pointer)
return -EINVAL;
package = buffer.pointer;
if (package->type != ACPI_TYPE_PACKAGE || package->package.count != 2)
goto out;
rev = package->package.elements[0].integer.value;
num = package->package.elements[1].integer.value;
if (rev != 1)
if (rev != 1 || num < 0)
goto out;
*num_cpus = num;
ret = 0;
@ -409,7 +415,7 @@ static void acpi_pad_ost(acpi_handle handle, int stat,
static void acpi_pad_handle_notify(acpi_handle handle)
{
int num_cpus, ret;
int num_cpus;
uint32_t idle_cpus;
mutex_lock(&isolated_cpus_lock);
@ -417,12 +423,9 @@ static void acpi_pad_handle_notify(acpi_handle handle)
mutex_unlock(&isolated_cpus_lock);
return;
}
ret = acpi_pad_idle_cpus(num_cpus);
acpi_pad_idle_cpus(num_cpus);
idle_cpus = acpi_pad_idle_cpus_num();
if (!ret)
acpi_pad_ost(handle, 0, idle_cpus);
else
acpi_pad_ost(handle, 1, 0);
acpi_pad_ost(handle, 0, idle_cpus);
mutex_unlock(&isolated_cpus_lock);
}