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ACPI: power: don't cache power resource state
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ACPI may change power resource state behind our back, so don't
keep our local copy, which may not be valid.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
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Alexey Starikovskiy authored and Len Brown committed Oct 25, 2007
1 parent 95b937e commit c35923b
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Showing 2 changed files with 26 additions and 43 deletions.
6 changes: 2 additions & 4 deletions drivers/acpi/bus.c
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Original file line number Diff line number Diff line change
Expand Up @@ -198,11 +198,9 @@ int acpi_bus_set_power(acpi_handle handle, int state)
return -ENODEV;
}
/*
* Get device's current power state if it's unknown
* This means device power state isn't initialized or previous setting failed
* Get device's current power state
*/
if ((device->power.state == ACPI_STATE_UNKNOWN) || device->flags.force_power_state)
acpi_bus_get_power(device->handle, &device->power.state);
acpi_bus_get_power(device->handle, &device->power.state);
if ((state == device->power.state) && !device->flags.force_power_state) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
state));
Expand Down
63 changes: 24 additions & 39 deletions drivers/acpi/power.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -86,7 +86,6 @@ struct acpi_power_resource {
acpi_bus_id name;
u32 system_level;
u32 order;
int state;
struct mutex resource_lock;
struct list_head reference;
};
Expand Down Expand Up @@ -128,33 +127,31 @@ acpi_power_get_context(acpi_handle handle,
return 0;
}

static int acpi_power_get_state(struct acpi_power_resource *resource)
static int acpi_power_get_state(struct acpi_power_resource *resource, int *state)
{
acpi_status status = AE_OK;
unsigned long sta = 0;


if (!resource)
if (!resource || !state)
return -EINVAL;

status = acpi_evaluate_integer(resource->device->handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status))
return -ENODEV;

if (sta & 0x01)
resource->state = ACPI_POWER_RESOURCE_STATE_ON;
else
resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
*state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
ACPI_POWER_RESOURCE_STATE_OFF;

ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
resource->name, resource->state ? "on" : "off"));
resource->name, state ? "on" : "off"));

return 0;
}

static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
{
int result = 0;
int result = 0, state1;
struct acpi_power_resource *resource = NULL;
u32 i = 0;

Expand All @@ -168,11 +165,11 @@ static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
result = acpi_power_get_context(list->handles[i], &resource);
if (result)
return result;
result = acpi_power_get_state(resource);
result = acpi_power_get_state(resource, &state1);
if (result)
return result;

*state = resource->state;
*state = state1;

if (*state != ACPI_POWER_RESOURCE_STATE_ON)
break;
Expand All @@ -186,7 +183,7 @@ static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)

static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
{
int result = 0;
int result = 0, state;
int found = 0;
acpi_status status = AE_OK;
struct acpi_power_resource *resource = NULL;
Expand Down Expand Up @@ -224,20 +221,14 @@ static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
}
mutex_unlock(&resource->resource_lock);

if (resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already on\n",
resource->name));
return 0;
}

status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;

result = acpi_power_get_state(resource);
result = acpi_power_get_state(resource, &state);
if (result)
return result;
if (resource->state != ACPI_POWER_RESOURCE_STATE_ON)
if (state != ACPI_POWER_RESOURCE_STATE_ON)
return -ENOEXEC;

/* Update the power resource's _device_ power state */
Expand All @@ -250,7 +241,7 @@ static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)

static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
{
int result = 0;
int result = 0, state;
acpi_status status = AE_OK;
struct acpi_power_resource *resource = NULL;
struct list_head *node, *next;
Expand Down Expand Up @@ -281,20 +272,14 @@ static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
}
mutex_unlock(&resource->resource_lock);

if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
resource->name));
return 0;
}

status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;

result = acpi_power_get_state(resource);
result = acpi_power_get_state(resource, &state);
if (result)
return result;
if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF)
if (state != ACPI_POWER_RESOURCE_STATE_OFF)
return -ENOEXEC;

/* Update the power resource's _device_ power state */
Expand Down Expand Up @@ -494,7 +479,7 @@ static struct proc_dir_entry *acpi_power_dir;
static int acpi_power_seq_show(struct seq_file *seq, void *offset)
{
int count = 0;
int result = 0;
int result = 0, state;
struct acpi_power_resource *resource = NULL;
struct list_head *node, *next;
struct acpi_power_reference *ref;
Expand All @@ -505,12 +490,12 @@ static int acpi_power_seq_show(struct seq_file *seq, void *offset)
if (!resource)
goto end;

result = acpi_power_get_state(resource);
result = acpi_power_get_state(resource, &state);
if (result)
goto end;

seq_puts(seq, "state: ");
switch (resource->state) {
switch (state) {
case ACPI_POWER_RESOURCE_STATE_ON:
seq_puts(seq, "on\n");
break;
Expand Down Expand Up @@ -591,7 +576,7 @@ static int acpi_power_remove_fs(struct acpi_device *device)

static int acpi_power_add(struct acpi_device *device)
{
int result = 0;
int result = 0, state;
acpi_status status = AE_OK;
struct acpi_power_resource *resource = NULL;
union acpi_object acpi_object;
Expand Down Expand Up @@ -622,11 +607,11 @@ static int acpi_power_add(struct acpi_device *device)
resource->system_level = acpi_object.power_resource.system_level;
resource->order = acpi_object.power_resource.resource_order;

result = acpi_power_get_state(resource);
result = acpi_power_get_state(resource, &state);
if (result)
goto end;

switch (resource->state) {
switch (state) {
case ACPI_POWER_RESOURCE_STATE_ON:
device->power.state = ACPI_STATE_D0;
break;
Expand All @@ -643,7 +628,7 @@ static int acpi_power_add(struct acpi_device *device)
goto end;

printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
acpi_device_bid(device), resource->state ? "on" : "off");
acpi_device_bid(device), state ? "on" : "off");

end:
if (result)
Expand Down Expand Up @@ -680,7 +665,7 @@ static int acpi_power_remove(struct acpi_device *device, int type)

static int acpi_power_resume(struct acpi_device *device)
{
int result = 0;
int result = 0, state;
struct acpi_power_resource *resource = NULL;
struct acpi_power_reference *ref;

Expand All @@ -689,12 +674,12 @@ static int acpi_power_resume(struct acpi_device *device)

resource = (struct acpi_power_resource *)acpi_driver_data(device);

result = acpi_power_get_state(resource);
result = acpi_power_get_state(resource, &state);
if (result)
return result;

mutex_lock(&resource->resource_lock);
if ((resource->state == ACPI_POWER_RESOURCE_STATE_OFF) &&
if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
!list_empty(&resource->reference)) {
ref = container_of(resource->reference.next, struct acpi_power_reference, node);
mutex_unlock(&resource->resource_lock);
Expand Down

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