static void lpi_device_get_constraints()

in x86/s2idle.c [180:288]

• 85 lines of code
• 19 McCabe index (conditional complexity)

static void lpi_device_get_constraints(void)
{
	union acpi_object *out_obj;
	int i;

	out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid,
					  1, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
					  NULL, ACPI_TYPE_PACKAGE);

	acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
			  out_obj ? "successful" : "failed");

	if (!out_obj)
		return;

	lpi_constraints_table = kcalloc(out_obj->package.count,
					sizeof(*lpi_constraints_table),
					GFP_KERNEL);
	if (!lpi_constraints_table)
		goto free_acpi_buffer;

	acpi_handle_debug(lps0_device_handle, "LPI: constraints list begin:\n");

	for (i = 0; i < out_obj->package.count; i++) {
		struct lpi_constraints *constraint;
		acpi_status status;
		union acpi_object *package = &out_obj->package.elements[i];
		struct lpi_device_info info = { };
		int package_count = 0, j;

		if (!package)
			continue;

		for (j = 0; j < package->package.count; ++j) {
			union acpi_object *element =
					&(package->package.elements[j]);

			switch (element->type) {
			case ACPI_TYPE_INTEGER:
				info.enabled = element->integer.value;
				break;
			case ACPI_TYPE_STRING:
				info.name = element->string.pointer;
				break;
			case ACPI_TYPE_PACKAGE:
				package_count = element->package.count;
				info.package = element->package.elements;
				break;
			}
		}

		if (!info.enabled || !info.package || !info.name)
			continue;

		constraint = &lpi_constraints_table[lpi_constraints_table_size];

		status = acpi_get_handle(NULL, info.name, &constraint->handle);
		if (ACPI_FAILURE(status))
			continue;

		acpi_handle_debug(lps0_device_handle,
				  "index:%d Name:%s\n", i, info.name);

		constraint->min_dstate = -1;

		for (j = 0; j < package_count; ++j) {
			union acpi_object *info_obj = &info.package[j];
			union acpi_object *cnstr_pkg;
			union acpi_object *obj;
			struct lpi_device_constraint dev_info;

			switch (info_obj->type) {
			case ACPI_TYPE_INTEGER:
				/* version */
				break;
			case ACPI_TYPE_PACKAGE:
				if (info_obj->package.count < 2)
					break;

				cnstr_pkg = info_obj->package.elements;
				obj = &cnstr_pkg[0];
				dev_info.uid = obj->integer.value;
				obj = &cnstr_pkg[1];
				dev_info.min_dstate = obj->integer.value;

				acpi_handle_debug(lps0_device_handle,
					"uid:%d min_dstate:%s\n",
					dev_info.uid,
					acpi_power_state_string(dev_info.min_dstate));

				constraint->min_dstate = dev_info.min_dstate;
				break;
			}
		}

		if (constraint->min_dstate < 0) {
			acpi_handle_debug(lps0_device_handle,
					  "Incomplete constraint defined\n");
			continue;
		}

		lpi_constraints_table_size++;
	}

	acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");

free_acpi_buffer:
	ACPI_FREE(out_obj);
}