On Monday, 22 October 2007 12:19, Alexey Starikovskiy wrote:
> 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@xxxxxxx>
> ---
>
> drivers/acpi/bus.c | 6 ++---
> drivers/acpi/power.c | 63 +++++++++++++++++++-------------------------------
> 2 files changed, 26 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index fb2cff9..fdee82d 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -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));
> diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
> index 57b9a29..af1769a 100644
> --- a/drivers/acpi/power.c
> +++ b/drivers/acpi/power.c
> @@ -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;
> };
> @@ -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;
This is a tiny bit inconsistent with the instances below where the local
variable is called "state" (ie. without the "1"). I'd just call the argument "state_p"
and the auxiliary variable "state".
> struct acpi_power_resource *resource = NULL;
> u32 i = 0;
>
> @@ -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;
> @@ -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;
> @@ -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 */
> @@ -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;
> @@ -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 */
> @@ -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;
> @@ -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;
> @@ -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;
> @@ -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;
> @@ -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)
> @@ -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;
>
> @@ -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);
>
>
>
--
"Premature optimization is the root of all evil." - Donald Knuth
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