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ACPI / property: Drop size_prop from acpi_dev_get_property_reference() 

The size_prop argument of the recently added function
acpi_dev_get_property_reference() is not used by the only current
caller of that function and is very unlikely to be used at any time
going forward.

Namely, for a property whose value is a list of items each containing
a references to a device object possibly accompanied by some integers,
the number of items in the list can always be computed as the number
of elements of type ACPI_TYPE_LOCAL_REFERENCE in the property package.
Thus it should never be necessary to provide an additional "cells"
property with a value equal to the number of items in that list.  It
also should never be necessary to provide a "cells" property specifying
how many integers are supposed to be following each reference.

For this reason, drop the size_prop argument from
acpi_dev_get_property_reference() and update its caller accordingly.

Link: http://marc.info/?l=linux-kernel&m=141511255610556&w=2
Suggested-by: Grant Likely <grant.likely@linaro.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki 2014-11-05 00:29:07 +01:00
parent c673a2b400
commit 60ba032ed7
3 changed files with 18 additions and 48 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
drivers/acpi/property.c
View File

@ -273,25 +273,21 @@ EXPORT_SYMBOL_GPL(acpi_dev_get_property_array);
* acpi_dev_get_property_reference - returns handle to the referenced object
* @adev: ACPI device to get property
* @name: Name of the property
* @size_prop: Name of the "size" property in referenced object
* @index: Index of the reference to return
* @args: Location to store the returned reference with optional arguments
*
* Find property with @name, verifify that it is a package containing at least
* one object reference and if so, store the ACPI device object pointer to the
* target object in @args->adev.
* target object in @args->adev. If the reference includes arguments, store
* them in the @args->args[] array.
*
* If the reference includes arguments (@size_prop is not %NULL) follow the
* reference and check whether or not there is an integer property @size_prop
* under the target object and if so, whether or not its value matches the
* number of arguments that follow the reference. If there's more than one
* reference in the property value package, @index is used to select the one to
* return.
* If there's more than one reference in the property value package, @index is
* used to select the one to return.
*
* Return: %0 on success, negative error code on failure.
*/
int acpi_dev_get_property_reference(struct acpi_device *adev, const char *name,
const char *size_prop, size_t index,
int acpi_dev_get_property_reference(struct acpi_device *adev,
const char *name, size_t index,
struct acpi_reference_args *args)
{
const union acpi_object *element, *end;
@ -308,7 +304,7 @@ int acpi_dev_get_property_reference(struct acpi_device *adev, const char *name,
* return that reference then.
*/
if (obj->type == ACPI_TYPE_LOCAL_REFERENCE) {
if (size_prop || index)
if (index)
return -EINVAL;
ret = acpi_bus_get_device(obj->reference.handle, &device);
@ -348,42 +344,16 @@ int acpi_dev_get_property_reference(struct acpi_device *adev, const char *name,
element++;
nargs = 0;
if (size_prop) {
const union acpi_object *prop;
/* assume following integer elements are all args */
for (i = 0; element + i < end; i++) {
int type = element[i].type;
/*
* Find out how many arguments the refenced object
* expects by reading its size_prop property.
*/
ret = acpi_dev_get_property(device, size_prop,
ACPI_TYPE_INTEGER, &prop);
if (ret)
return ret;
nargs = prop->integer.value;
if (nargs > MAX_ACPI_REFERENCE_ARGS
|| element + nargs > end)
if (type == ACPI_TYPE_INTEGER)
nargs++;
else if (type == ACPI_TYPE_LOCAL_REFERENCE)
break;
else
return -EPROTO;
/*
* Skip to the start of the arguments and verify
* that they all are in fact integers.
*/
for (i = 0; i < nargs; i++)
if (element[i].type != ACPI_TYPE_INTEGER)
return -EPROTO;
} else {
/* assume following integer elements are all args */
for (i = 0; element + i < end; i++) {
int type = element[i].type;
if (type == ACPI_TYPE_INTEGER)
nargs++;
else if (type == ACPI_TYPE_LOCAL_REFERENCE)
break;
else
return -EPROTO;
}
}
if (idx++ == index) {

2
drivers/gpio/gpiolib-acpi.c
View File

@ -405,7 +405,7 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
memset(&args, 0, sizeof(args));
ret = acpi_dev_get_property_reference(adev, propname, NULL,
ret = acpi_dev_get_property_reference(adev, propname,
index, &args);
if (ret) {
bool found = acpi_get_driver_gpio_data(adev, propname,

4
include/linux/acpi.h
View File

@ -718,8 +718,8 @@ int acpi_dev_get_property(struct acpi_device *adev, const char *name,
int acpi_dev_get_property_array(struct acpi_device *adev, const char *name,
acpi_object_type type,
const union acpi_object **obj);
int acpi_dev_get_property_reference(struct acpi_device *adev, const char *name,
const char *cells_name, size_t index,
int acpi_dev_get_property_reference(struct acpi_device *adev,
const char *name, size_t index,
struct acpi_reference_args *args);
int acpi_dev_prop_get(struct acpi_device *adev, const char *propname,