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-rw-r--r--drivers/acpi/x86/s2idle.c669
1 files changed, 669 insertions, 0 deletions
diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
new file mode 100644
index 0000000000..08f7c67082
--- /dev/null
+++ b/drivers/acpi/x86/s2idle.c
@@ -0,0 +1,669 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Architecture-specific ACPI-based support for suspend-to-idle.
+ *
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ * Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
+ * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ *
+ * On platforms supporting the Low Power S0 Idle interface there is an ACPI
+ * device object with the PNP0D80 compatible device ID (System Power Management
+ * Controller) and a specific _DSM method under it. That method, if present,
+ * can be used to indicate to the platform that the OS is transitioning into a
+ * low-power state in which certain types of activity are not desirable or that
+ * it is leaving such a state, which allows the platform to adjust its operation
+ * mode accordingly.
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/dmi.h>
+#include <linux/suspend.h>
+
+#include "../sleep.h"
+
+#ifdef CONFIG_SUSPEND
+
+static bool sleep_no_lps0 __read_mostly;
+module_param(sleep_no_lps0, bool, 0644);
+MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface");
+
+static const struct acpi_device_id lps0_device_ids[] = {
+ {"PNP0D80", },
+ {"", },
+};
+
+/* Microsoft platform agnostic UUID */
+#define ACPI_LPS0_DSM_UUID_MICROSOFT "11e00d56-ce64-47ce-837b-1f898f9aa461"
+
+#define ACPI_LPS0_DSM_UUID "c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"
+
+#define ACPI_LPS0_GET_DEVICE_CONSTRAINTS 1
+#define ACPI_LPS0_SCREEN_OFF 3
+#define ACPI_LPS0_SCREEN_ON 4
+#define ACPI_LPS0_ENTRY 5
+#define ACPI_LPS0_EXIT 6
+#define ACPI_LPS0_MS_ENTRY 7
+#define ACPI_LPS0_MS_EXIT 8
+
+/* AMD */
+#define ACPI_LPS0_DSM_UUID_AMD "e3f32452-febc-43ce-9039-932122d37721"
+#define ACPI_LPS0_ENTRY_AMD 2
+#define ACPI_LPS0_EXIT_AMD 3
+#define ACPI_LPS0_SCREEN_OFF_AMD 4
+#define ACPI_LPS0_SCREEN_ON_AMD 5
+
+static acpi_handle lps0_device_handle;
+static guid_t lps0_dsm_guid;
+static int lps0_dsm_func_mask;
+
+static guid_t lps0_dsm_guid_microsoft;
+static int lps0_dsm_func_mask_microsoft;
+static int lps0_dsm_state;
+
+/* Device constraint entry structure */
+struct lpi_device_info {
+ char *name;
+ int enabled;
+ union acpi_object *package;
+};
+
+/* Constraint package structure */
+struct lpi_device_constraint {
+ int uid;
+ int min_dstate;
+ int function_states;
+};
+
+struct lpi_constraints {
+ acpi_handle handle;
+ int min_dstate;
+};
+
+/* AMD Constraint package structure */
+struct lpi_device_constraint_amd {
+ char *name;
+ int enabled;
+ int function_states;
+ int min_dstate;
+};
+
+static LIST_HEAD(lps0_s2idle_devops_head);
+
+static struct lpi_constraints *lpi_constraints_table;
+static int lpi_constraints_table_size;
+static int rev_id;
+
+#define for_each_lpi_constraint(entry) \
+ for (int i = 0; \
+ entry = &lpi_constraints_table[i], i < lpi_constraints_table_size; \
+ i++)
+
+static void lpi_device_get_constraints_amd(void)
+{
+ union acpi_object *out_obj;
+ int i, j, k;
+
+ out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid,
+ rev_id, 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;
+
+ for (i = 0; i < out_obj->package.count; i++) {
+ union acpi_object *package = &out_obj->package.elements[i];
+
+ if (package->type == ACPI_TYPE_PACKAGE) {
+ if (lpi_constraints_table) {
+ acpi_handle_err(lps0_device_handle,
+ "Duplicate constraints list\n");
+ goto free_acpi_buffer;
+ }
+
+ lpi_constraints_table = kcalloc(package->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 (j = 0; j < package->package.count; j++) {
+ union acpi_object *info_obj = &package->package.elements[j];
+ struct lpi_device_constraint_amd dev_info = {};
+ struct lpi_constraints *list;
+ acpi_status status;
+
+ list = &lpi_constraints_table[lpi_constraints_table_size];
+
+ for (k = 0; k < info_obj->package.count; k++) {
+ union acpi_object *obj = &info_obj->package.elements[k];
+
+ switch (k) {
+ case 0:
+ dev_info.enabled = obj->integer.value;
+ break;
+ case 1:
+ dev_info.name = obj->string.pointer;
+ break;
+ case 2:
+ dev_info.function_states = obj->integer.value;
+ break;
+ case 3:
+ dev_info.min_dstate = obj->integer.value;
+ break;
+ }
+ }
+
+ acpi_handle_debug(lps0_device_handle,
+ "Name:%s, Enabled: %d, States: %d, MinDstate: %d\n",
+ dev_info.name,
+ dev_info.enabled,
+ dev_info.function_states,
+ dev_info.min_dstate);
+
+ if (!dev_info.enabled || !dev_info.name ||
+ !dev_info.min_dstate)
+ continue;
+
+ status = acpi_get_handle(NULL, dev_info.name, &list->handle);
+ if (ACPI_FAILURE(status))
+ continue;
+
+ list->min_dstate = dev_info.min_dstate;
+
+ lpi_constraints_table_size++;
+ }
+ }
+ }
+
+ acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");
+
+free_acpi_buffer:
+ ACPI_FREE(out_obj);
+}
+
+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);
+}
+
+/**
+ * acpi_get_lps0_constraint - Get the LPS0 constraint for a device.
+ * @adev: Device to get the constraint for.
+ *
+ * The LPS0 constraint is the shallowest (minimum) power state in which the
+ * device can be so as to allow the platform as a whole to achieve additional
+ * energy conservation by utilizing a system-wide low-power state.
+ *
+ * Returns:
+ * - ACPI power state value of the constraint for @adev on success.
+ * - Otherwise, ACPI_STATE_UNKNOWN.
+ */
+int acpi_get_lps0_constraint(struct acpi_device *adev)
+{
+ struct lpi_constraints *entry;
+
+ for_each_lpi_constraint(entry) {
+ if (adev->handle == entry->handle)
+ return entry->min_dstate;
+ }
+
+ return ACPI_STATE_UNKNOWN;
+}
+
+static void lpi_check_constraints(void)
+{
+ struct lpi_constraints *entry;
+
+ for_each_lpi_constraint(entry) {
+ struct acpi_device *adev = acpi_fetch_acpi_dev(entry->handle);
+
+ if (!adev)
+ continue;
+
+ acpi_handle_debug(entry->handle,
+ "LPI: required min power state:%s current power state:%s\n",
+ acpi_power_state_string(entry->min_dstate),
+ acpi_power_state_string(adev->power.state));
+
+ if (!adev->flags.power_manageable) {
+ acpi_handle_info(entry->handle, "LPI: Device not power manageable\n");
+ entry->handle = NULL;
+ continue;
+ }
+
+ if (adev->power.state < entry->min_dstate)
+ acpi_handle_info(entry->handle,
+ "LPI: Constraint not met; min power state:%s current power state:%s\n",
+ acpi_power_state_string(entry->min_dstate),
+ acpi_power_state_string(adev->power.state));
+ }
+}
+
+static bool acpi_s2idle_vendor_amd(void)
+{
+ return boot_cpu_data.x86_vendor == X86_VENDOR_AMD;
+}
+
+static const char *acpi_sleep_dsm_state_to_str(unsigned int state)
+{
+ if (lps0_dsm_func_mask_microsoft || !acpi_s2idle_vendor_amd()) {
+ switch (state) {
+ case ACPI_LPS0_SCREEN_OFF:
+ return "screen off";
+ case ACPI_LPS0_SCREEN_ON:
+ return "screen on";
+ case ACPI_LPS0_ENTRY:
+ return "lps0 entry";
+ case ACPI_LPS0_EXIT:
+ return "lps0 exit";
+ case ACPI_LPS0_MS_ENTRY:
+ return "lps0 ms entry";
+ case ACPI_LPS0_MS_EXIT:
+ return "lps0 ms exit";
+ }
+ } else {
+ switch (state) {
+ case ACPI_LPS0_SCREEN_ON_AMD:
+ return "screen on";
+ case ACPI_LPS0_SCREEN_OFF_AMD:
+ return "screen off";
+ case ACPI_LPS0_ENTRY_AMD:
+ return "lps0 entry";
+ case ACPI_LPS0_EXIT_AMD:
+ return "lps0 exit";
+ }
+ }
+
+ return "unknown";
+}
+
+static void acpi_sleep_run_lps0_dsm(unsigned int func, unsigned int func_mask, guid_t dsm_guid)
+{
+ union acpi_object *out_obj;
+
+ if (!(func_mask & (1 << func)))
+ return;
+
+ out_obj = acpi_evaluate_dsm(lps0_device_handle, &dsm_guid,
+ rev_id, func, NULL);
+ ACPI_FREE(out_obj);
+
+ lps0_dsm_state = func;
+ if (pm_debug_messages_on) {
+ acpi_handle_info(lps0_device_handle,
+ "%s transitioned to state %s\n",
+ out_obj ? "Successfully" : "Failed to",
+ acpi_sleep_dsm_state_to_str(lps0_dsm_state));
+ }
+}
+
+
+static int validate_dsm(acpi_handle handle, const char *uuid, int rev, guid_t *dsm_guid)
+{
+ union acpi_object *obj;
+ int ret = -EINVAL;
+
+ guid_parse(uuid, dsm_guid);
+ obj = acpi_evaluate_dsm(handle, dsm_guid, rev, 0, NULL);
+
+ /* Check if the _DSM is present and as expected. */
+ if (!obj || obj->type != ACPI_TYPE_BUFFER || obj->buffer.length == 0 ||
+ obj->buffer.length > sizeof(u32)) {
+ acpi_handle_debug(handle,
+ "_DSM UUID %s rev %d function 0 evaluation failed\n", uuid, rev);
+ goto out;
+ }
+
+ ret = *(int *)obj->buffer.pointer;
+ acpi_handle_debug(handle, "_DSM UUID %s rev %d function mask: 0x%x\n", uuid, rev, ret);
+
+out:
+ ACPI_FREE(obj);
+ return ret;
+}
+
+struct amd_lps0_hid_device_data {
+ const bool check_off_by_one;
+};
+
+static const struct amd_lps0_hid_device_data amd_picasso = {
+ .check_off_by_one = true,
+};
+
+static const struct amd_lps0_hid_device_data amd_cezanne = {
+ .check_off_by_one = false,
+};
+
+static const struct acpi_device_id amd_hid_ids[] = {
+ {"AMD0004", (kernel_ulong_t)&amd_picasso, },
+ {"AMD0005", (kernel_ulong_t)&amd_picasso, },
+ {"AMDI0005", (kernel_ulong_t)&amd_picasso, },
+ {"AMDI0006", (kernel_ulong_t)&amd_cezanne, },
+ {}
+};
+
+static int lps0_device_attach(struct acpi_device *adev,
+ const struct acpi_device_id *not_used)
+{
+ if (lps0_device_handle)
+ return 0;
+
+ lps0_dsm_func_mask_microsoft = validate_dsm(adev->handle,
+ ACPI_LPS0_DSM_UUID_MICROSOFT, 0,
+ &lps0_dsm_guid_microsoft);
+ if (acpi_s2idle_vendor_amd()) {
+ static const struct acpi_device_id *dev_id;
+ const struct amd_lps0_hid_device_data *data;
+
+ for (dev_id = &amd_hid_ids[0]; dev_id->id[0]; dev_id++)
+ if (acpi_dev_hid_uid_match(adev, dev_id->id, NULL))
+ break;
+ if (dev_id->id[0])
+ data = (const struct amd_lps0_hid_device_data *) dev_id->driver_data;
+ else
+ data = &amd_cezanne;
+ lps0_dsm_func_mask = validate_dsm(adev->handle,
+ ACPI_LPS0_DSM_UUID_AMD, rev_id, &lps0_dsm_guid);
+ if (lps0_dsm_func_mask > 0x3 && data->check_off_by_one) {
+ lps0_dsm_func_mask = (lps0_dsm_func_mask << 1) | 0x1;
+ acpi_handle_debug(adev->handle, "_DSM UUID %s: Adjusted function mask: 0x%x\n",
+ ACPI_LPS0_DSM_UUID_AMD, lps0_dsm_func_mask);
+ } else if (lps0_dsm_func_mask_microsoft > 0 && rev_id) {
+ lps0_dsm_func_mask_microsoft = -EINVAL;
+ acpi_handle_debug(adev->handle, "_DSM Using AMD method\n");
+ }
+ } else {
+ rev_id = 1;
+ lps0_dsm_func_mask = validate_dsm(adev->handle,
+ ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid);
+ lps0_dsm_func_mask_microsoft = -EINVAL;
+ }
+
+ if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0)
+ return 0; //function evaluation failed
+
+ lps0_device_handle = adev->handle;
+
+ if (acpi_s2idle_vendor_amd())
+ lpi_device_get_constraints_amd();
+ else
+ lpi_device_get_constraints();
+
+ /*
+ * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in
+ * the FADT and the default suspend mode was not set from the command
+ * line.
+ */
+ if ((acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) &&
+ mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3) {
+ mem_sleep_current = PM_SUSPEND_TO_IDLE;
+ pr_info("Low-power S0 idle used by default for system suspend\n");
+ }
+
+ /*
+ * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the
+ * EC GPE to be enabled while suspended for certain wakeup devices to
+ * work, so mark it as wakeup-capable.
+ */
+ acpi_ec_mark_gpe_for_wake();
+
+ return 0;
+}
+
+static struct acpi_scan_handler lps0_handler = {
+ .ids = lps0_device_ids,
+ .attach = lps0_device_attach,
+};
+
+int acpi_s2idle_prepare_late(void)
+{
+ struct acpi_s2idle_dev_ops *handler;
+
+ if (!lps0_device_handle || sleep_no_lps0)
+ return 0;
+
+ if (pm_debug_messages_on)
+ lpi_check_constraints();
+
+ /* Screen off */
+ if (lps0_dsm_func_mask > 0)
+ acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
+ ACPI_LPS0_SCREEN_OFF_AMD :
+ ACPI_LPS0_SCREEN_OFF,
+ lps0_dsm_func_mask, lps0_dsm_guid);
+
+ if (lps0_dsm_func_mask_microsoft > 0)
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF,
+ lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
+
+ /* LPS0 entry */
+ if (lps0_dsm_func_mask > 0)
+ acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
+ ACPI_LPS0_ENTRY_AMD :
+ ACPI_LPS0_ENTRY,
+ lps0_dsm_func_mask, lps0_dsm_guid);
+ if (lps0_dsm_func_mask_microsoft > 0) {
+ /* modern standby entry */
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY,
+ lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
+ lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
+ }
+
+ list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
+ if (handler->prepare)
+ handler->prepare();
+ }
+
+ return 0;
+}
+
+void acpi_s2idle_check(void)
+{
+ struct acpi_s2idle_dev_ops *handler;
+
+ if (!lps0_device_handle || sleep_no_lps0)
+ return;
+
+ list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
+ if (handler->check)
+ handler->check();
+ }
+}
+
+void acpi_s2idle_restore_early(void)
+{
+ struct acpi_s2idle_dev_ops *handler;
+
+ if (!lps0_device_handle || sleep_no_lps0)
+ return;
+
+ list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node)
+ if (handler->restore)
+ handler->restore();
+
+ /* LPS0 exit */
+ if (lps0_dsm_func_mask > 0)
+ acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
+ ACPI_LPS0_EXIT_AMD :
+ ACPI_LPS0_EXIT,
+ lps0_dsm_func_mask, lps0_dsm_guid);
+ if (lps0_dsm_func_mask_microsoft > 0)
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT,
+ lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
+
+ /* Modern standby exit */
+ if (lps0_dsm_func_mask_microsoft > 0)
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT,
+ lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
+
+ /* Screen on */
+ if (lps0_dsm_func_mask_microsoft > 0)
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON,
+ lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
+ if (lps0_dsm_func_mask > 0)
+ acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
+ ACPI_LPS0_SCREEN_ON_AMD :
+ ACPI_LPS0_SCREEN_ON,
+ lps0_dsm_func_mask, lps0_dsm_guid);
+}
+
+static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
+ .begin = acpi_s2idle_begin,
+ .prepare = acpi_s2idle_prepare,
+ .prepare_late = acpi_s2idle_prepare_late,
+ .check = acpi_s2idle_check,
+ .wake = acpi_s2idle_wake,
+ .restore_early = acpi_s2idle_restore_early,
+ .restore = acpi_s2idle_restore,
+ .end = acpi_s2idle_end,
+};
+
+void __init acpi_s2idle_setup(void)
+{
+ acpi_scan_add_handler(&lps0_handler);
+ s2idle_set_ops(&acpi_s2idle_ops_lps0);
+}
+
+int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg)
+{
+ unsigned int sleep_flags;
+
+ if (!lps0_device_handle || sleep_no_lps0)
+ return -ENODEV;
+
+ sleep_flags = lock_system_sleep();
+ list_add(&arg->list_node, &lps0_s2idle_devops_head);
+ unlock_system_sleep(sleep_flags);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_register_lps0_dev);
+
+void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg)
+{
+ unsigned int sleep_flags;
+
+ if (!lps0_device_handle || sleep_no_lps0)
+ return;
+
+ sleep_flags = lock_system_sleep();
+ list_del(&arg->list_node);
+ unlock_system_sleep(sleep_flags);
+}
+EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev);
+
+#endif /* CONFIG_SUSPEND */