Commit 3b8cb427 authored by Chen Gong's avatar Chen Gong Committed by Len Brown
Browse files

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: default avatarChen Gong <gong.chen@linux.intel.com>
Acked-by: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 22763c5c

drivers/acpi/acpi_pad.c

+20 −17
Original line number Diff line number Diff line
@@ -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);

	mutex_unlock(&isolated_cpus_lock);

}

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