linux_dsm_epyc7002/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
Rex Zhu 589941e1a2 drm/amdgpu: Notify sbios device ready before send request
it is required if a platform supports PCIe root complex
core voltage reduction. After receiving this notification,
SBIOS can apply default PCIe root complex power policy.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
2018-03-05 15:38:27 -05:00

724 lines
20 KiB
C

/*
* Copyright 2012 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
*/
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#include <linux/power_supply.h>
#include <linux/pm_runtime.h>
#include <acpi/video.h>
#include <drm/drmP.h>
#include <drm/drm_crtc_helper.h>
#include "amdgpu.h"
#include "amdgpu_pm.h"
#include "amd_acpi.h"
#include "atom.h"
/* Call the ATIF method
*/
/**
* amdgpu_atif_call - call an ATIF method
*
* @handle: acpi handle
* @function: the ATIF function to execute
* @params: ATIF function params
*
* Executes the requested ATIF function (all asics).
* Returns a pointer to the acpi output buffer.
*/
static union acpi_object *amdgpu_atif_call(acpi_handle handle, int function,
struct acpi_buffer *params)
{
acpi_status status;
union acpi_object atif_arg_elements[2];
struct acpi_object_list atif_arg;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
atif_arg.count = 2;
atif_arg.pointer = &atif_arg_elements[0];
atif_arg_elements[0].type = ACPI_TYPE_INTEGER;
atif_arg_elements[0].integer.value = function;
if (params) {
atif_arg_elements[1].type = ACPI_TYPE_BUFFER;
atif_arg_elements[1].buffer.length = params->length;
atif_arg_elements[1].buffer.pointer = params->pointer;
} else {
/* We need a second fake parameter */
atif_arg_elements[1].type = ACPI_TYPE_INTEGER;
atif_arg_elements[1].integer.value = 0;
}
status = acpi_evaluate_object(handle, "ATIF", &atif_arg, &buffer);
/* Fail only if calling the method fails and ATIF is supported */
if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
DRM_DEBUG_DRIVER("failed to evaluate ATIF got %s\n",
acpi_format_exception(status));
kfree(buffer.pointer);
return NULL;
}
return buffer.pointer;
}
/**
* amdgpu_atif_parse_notification - parse supported notifications
*
* @n: supported notifications struct
* @mask: supported notifications mask from ATIF
*
* Use the supported notifications mask from ATIF function
* ATIF_FUNCTION_VERIFY_INTERFACE to determine what notifications
* are supported (all asics).
*/
static void amdgpu_atif_parse_notification(struct amdgpu_atif_notifications *n, u32 mask)
{
n->display_switch = mask & ATIF_DISPLAY_SWITCH_REQUEST_SUPPORTED;
n->expansion_mode_change = mask & ATIF_EXPANSION_MODE_CHANGE_REQUEST_SUPPORTED;
n->thermal_state = mask & ATIF_THERMAL_STATE_CHANGE_REQUEST_SUPPORTED;
n->forced_power_state = mask & ATIF_FORCED_POWER_STATE_CHANGE_REQUEST_SUPPORTED;
n->system_power_state = mask & ATIF_SYSTEM_POWER_SOURCE_CHANGE_REQUEST_SUPPORTED;
n->display_conf_change = mask & ATIF_DISPLAY_CONF_CHANGE_REQUEST_SUPPORTED;
n->px_gfx_switch = mask & ATIF_PX_GFX_SWITCH_REQUEST_SUPPORTED;
n->brightness_change = mask & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST_SUPPORTED;
n->dgpu_display_event = mask & ATIF_DGPU_DISPLAY_EVENT_SUPPORTED;
}
/**
* amdgpu_atif_parse_functions - parse supported functions
*
* @f: supported functions struct
* @mask: supported functions mask from ATIF
*
* Use the supported functions mask from ATIF function
* ATIF_FUNCTION_VERIFY_INTERFACE to determine what functions
* are supported (all asics).
*/
static void amdgpu_atif_parse_functions(struct amdgpu_atif_functions *f, u32 mask)
{
f->system_params = mask & ATIF_GET_SYSTEM_PARAMETERS_SUPPORTED;
f->sbios_requests = mask & ATIF_GET_SYSTEM_BIOS_REQUESTS_SUPPORTED;
f->select_active_disp = mask & ATIF_SELECT_ACTIVE_DISPLAYS_SUPPORTED;
f->lid_state = mask & ATIF_GET_LID_STATE_SUPPORTED;
f->get_tv_standard = mask & ATIF_GET_TV_STANDARD_FROM_CMOS_SUPPORTED;
f->set_tv_standard = mask & ATIF_SET_TV_STANDARD_IN_CMOS_SUPPORTED;
f->get_panel_expansion_mode = mask & ATIF_GET_PANEL_EXPANSION_MODE_FROM_CMOS_SUPPORTED;
f->set_panel_expansion_mode = mask & ATIF_SET_PANEL_EXPANSION_MODE_IN_CMOS_SUPPORTED;
f->temperature_change = mask & ATIF_TEMPERATURE_CHANGE_NOTIFICATION_SUPPORTED;
f->graphics_device_types = mask & ATIF_GET_GRAPHICS_DEVICE_TYPES_SUPPORTED;
}
/**
* amdgpu_atif_verify_interface - verify ATIF
*
* @handle: acpi handle
* @atif: amdgpu atif struct
*
* Execute the ATIF_FUNCTION_VERIFY_INTERFACE ATIF function
* to initialize ATIF and determine what features are supported
* (all asics).
* returns 0 on success, error on failure.
*/
static int amdgpu_atif_verify_interface(acpi_handle handle,
struct amdgpu_atif *atif)
{
union acpi_object *info;
struct atif_verify_interface output;
size_t size;
int err = 0;
info = amdgpu_atif_call(handle, ATIF_FUNCTION_VERIFY_INTERFACE, NULL);
if (!info)
return -EIO;
memset(&output, 0, sizeof(output));
size = *(u16 *) info->buffer.pointer;
if (size < 12) {
DRM_INFO("ATIF buffer is too small: %zu\n", size);
err = -EINVAL;
goto out;
}
size = min(sizeof(output), size);
memcpy(&output, info->buffer.pointer, size);
/* TODO: check version? */
DRM_DEBUG_DRIVER("ATIF version %u\n", output.version);
amdgpu_atif_parse_notification(&atif->notifications, output.notification_mask);
amdgpu_atif_parse_functions(&atif->functions, output.function_bits);
out:
kfree(info);
return err;
}
/**
* amdgpu_atif_get_notification_params - determine notify configuration
*
* @handle: acpi handle
* @n: atif notification configuration struct
*
* Execute the ATIF_FUNCTION_GET_SYSTEM_PARAMETERS ATIF function
* to determine if a notifier is used and if so which one
* (all asics). This is either Notify(VGA, 0x81) or Notify(VGA, n)
* where n is specified in the result if a notifier is used.
* Returns 0 on success, error on failure.
*/
static int amdgpu_atif_get_notification_params(acpi_handle handle,
struct amdgpu_atif_notification_cfg *n)
{
union acpi_object *info;
struct atif_system_params params;
size_t size;
int err = 0;
info = amdgpu_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_PARAMETERS, NULL);
if (!info) {
err = -EIO;
goto out;
}
size = *(u16 *) info->buffer.pointer;
if (size < 10) {
err = -EINVAL;
goto out;
}
memset(&params, 0, sizeof(params));
size = min(sizeof(params), size);
memcpy(&params, info->buffer.pointer, size);
DRM_DEBUG_DRIVER("SYSTEM_PARAMS: mask = %#x, flags = %#x\n",
params.flags, params.valid_mask);
params.flags = params.flags & params.valid_mask;
if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_NONE) {
n->enabled = false;
n->command_code = 0;
} else if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_81) {
n->enabled = true;
n->command_code = 0x81;
} else {
if (size < 11) {
err = -EINVAL;
goto out;
}
n->enabled = true;
n->command_code = params.command_code;
}
out:
DRM_DEBUG_DRIVER("Notification %s, command code = %#x\n",
(n->enabled ? "enabled" : "disabled"),
n->command_code);
kfree(info);
return err;
}
/**
* amdgpu_atif_get_sbios_requests - get requested sbios event
*
* @handle: acpi handle
* @req: atif sbios request struct
*
* Execute the ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS ATIF function
* to determine what requests the sbios is making to the driver
* (all asics).
* Returns 0 on success, error on failure.
*/
static int amdgpu_atif_get_sbios_requests(acpi_handle handle,
struct atif_sbios_requests *req)
{
union acpi_object *info;
size_t size;
int count = 0;
info = amdgpu_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS, NULL);
if (!info)
return -EIO;
size = *(u16 *)info->buffer.pointer;
if (size < 0xd) {
count = -EINVAL;
goto out;
}
memset(req, 0, sizeof(*req));
size = min(sizeof(*req), size);
memcpy(req, info->buffer.pointer, size);
DRM_DEBUG_DRIVER("SBIOS pending requests: %#x\n", req->pending);
count = hweight32(req->pending);
out:
kfree(info);
return count;
}
/**
* amdgpu_atif_handler - handle ATIF notify requests
*
* @adev: amdgpu_device pointer
* @event: atif sbios request struct
*
* Checks the acpi event and if it matches an atif event,
* handles it.
* Returns NOTIFY code
*/
static int amdgpu_atif_handler(struct amdgpu_device *adev,
struct acpi_bus_event *event)
{
struct amdgpu_atif *atif = &adev->atif;
struct atif_sbios_requests req;
acpi_handle handle;
int count;
DRM_DEBUG_DRIVER("event, device_class = %s, type = %#x\n",
event->device_class, event->type);
if (strcmp(event->device_class, ACPI_VIDEO_CLASS) != 0)
return NOTIFY_DONE;
if (!atif->notification_cfg.enabled ||
event->type != atif->notification_cfg.command_code)
/* Not our event */
return NOTIFY_DONE;
/* Check pending SBIOS requests */
handle = ACPI_HANDLE(&adev->pdev->dev);
count = amdgpu_atif_get_sbios_requests(handle, &req);
if (count <= 0)
return NOTIFY_DONE;
DRM_DEBUG_DRIVER("ATIF: %d pending SBIOS requests\n", count);
if (req.pending & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST) {
struct amdgpu_encoder *enc = atif->encoder_for_bl;
if (enc) {
struct amdgpu_encoder_atom_dig *dig = enc->enc_priv;
DRM_DEBUG_DRIVER("Changing brightness to %d\n",
req.backlight_level);
amdgpu_display_backlight_set_level(adev, enc, req.backlight_level);
#if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) || defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)
backlight_force_update(dig->bl_dev,
BACKLIGHT_UPDATE_HOTKEY);
#endif
}
}
if (req.pending & ATIF_DGPU_DISPLAY_EVENT) {
if ((adev->flags & AMD_IS_PX) &&
amdgpu_atpx_dgpu_req_power_for_displays()) {
pm_runtime_get_sync(adev->ddev->dev);
/* Just fire off a uevent and let userspace tell us what to do */
drm_helper_hpd_irq_event(adev->ddev);
pm_runtime_mark_last_busy(adev->ddev->dev);
pm_runtime_put_autosuspend(adev->ddev->dev);
}
}
/* TODO: check other events */
/* We've handled the event, stop the notifier chain. The ACPI interface
* overloads ACPI_VIDEO_NOTIFY_PROBE, we don't want to send that to
* userspace if the event was generated only to signal a SBIOS
* request.
*/
return NOTIFY_BAD;
}
/* Call the ATCS method
*/
/**
* amdgpu_atcs_call - call an ATCS method
*
* @handle: acpi handle
* @function: the ATCS function to execute
* @params: ATCS function params
*
* Executes the requested ATCS function (all asics).
* Returns a pointer to the acpi output buffer.
*/
static union acpi_object *amdgpu_atcs_call(acpi_handle handle, int function,
struct acpi_buffer *params)
{
acpi_status status;
union acpi_object atcs_arg_elements[2];
struct acpi_object_list atcs_arg;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
atcs_arg.count = 2;
atcs_arg.pointer = &atcs_arg_elements[0];
atcs_arg_elements[0].type = ACPI_TYPE_INTEGER;
atcs_arg_elements[0].integer.value = function;
if (params) {
atcs_arg_elements[1].type = ACPI_TYPE_BUFFER;
atcs_arg_elements[1].buffer.length = params->length;
atcs_arg_elements[1].buffer.pointer = params->pointer;
} else {
/* We need a second fake parameter */
atcs_arg_elements[1].type = ACPI_TYPE_INTEGER;
atcs_arg_elements[1].integer.value = 0;
}
status = acpi_evaluate_object(handle, "ATCS", &atcs_arg, &buffer);
/* Fail only if calling the method fails and ATIF is supported */
if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
DRM_DEBUG_DRIVER("failed to evaluate ATCS got %s\n",
acpi_format_exception(status));
kfree(buffer.pointer);
return NULL;
}
return buffer.pointer;
}
/**
* amdgpu_atcs_parse_functions - parse supported functions
*
* @f: supported functions struct
* @mask: supported functions mask from ATCS
*
* Use the supported functions mask from ATCS function
* ATCS_FUNCTION_VERIFY_INTERFACE to determine what functions
* are supported (all asics).
*/
static void amdgpu_atcs_parse_functions(struct amdgpu_atcs_functions *f, u32 mask)
{
f->get_ext_state = mask & ATCS_GET_EXTERNAL_STATE_SUPPORTED;
f->pcie_perf_req = mask & ATCS_PCIE_PERFORMANCE_REQUEST_SUPPORTED;
f->pcie_dev_rdy = mask & ATCS_PCIE_DEVICE_READY_NOTIFICATION_SUPPORTED;
f->pcie_bus_width = mask & ATCS_SET_PCIE_BUS_WIDTH_SUPPORTED;
}
/**
* amdgpu_atcs_verify_interface - verify ATCS
*
* @handle: acpi handle
* @atcs: amdgpu atcs struct
*
* Execute the ATCS_FUNCTION_VERIFY_INTERFACE ATCS function
* to initialize ATCS and determine what features are supported
* (all asics).
* returns 0 on success, error on failure.
*/
static int amdgpu_atcs_verify_interface(acpi_handle handle,
struct amdgpu_atcs *atcs)
{
union acpi_object *info;
struct atcs_verify_interface output;
size_t size;
int err = 0;
info = amdgpu_atcs_call(handle, ATCS_FUNCTION_VERIFY_INTERFACE, NULL);
if (!info)
return -EIO;
memset(&output, 0, sizeof(output));
size = *(u16 *) info->buffer.pointer;
if (size < 8) {
DRM_INFO("ATCS buffer is too small: %zu\n", size);
err = -EINVAL;
goto out;
}
size = min(sizeof(output), size);
memcpy(&output, info->buffer.pointer, size);
/* TODO: check version? */
DRM_DEBUG_DRIVER("ATCS version %u\n", output.version);
amdgpu_atcs_parse_functions(&atcs->functions, output.function_bits);
out:
kfree(info);
return err;
}
/**
* amdgpu_acpi_is_pcie_performance_request_supported
*
* @adev: amdgpu_device pointer
*
* Check if the ATCS pcie_perf_req and pcie_dev_rdy methods
* are supported (all asics).
* returns true if supported, false if not.
*/
bool amdgpu_acpi_is_pcie_performance_request_supported(struct amdgpu_device *adev)
{
struct amdgpu_atcs *atcs = &adev->atcs;
if (atcs->functions.pcie_perf_req && atcs->functions.pcie_dev_rdy)
return true;
return false;
}
/**
* amdgpu_acpi_pcie_notify_device_ready
*
* @adev: amdgpu_device pointer
*
* Executes the PCIE_DEVICE_READY_NOTIFICATION method
* (all asics).
* returns 0 on success, error on failure.
*/
int amdgpu_acpi_pcie_notify_device_ready(struct amdgpu_device *adev)
{
acpi_handle handle;
union acpi_object *info;
struct amdgpu_atcs *atcs = &adev->atcs;
/* Get the device handle */
handle = ACPI_HANDLE(&adev->pdev->dev);
if (!handle)
return -EINVAL;
if (!atcs->functions.pcie_dev_rdy)
return -EINVAL;
info = amdgpu_atcs_call(handle, ATCS_FUNCTION_PCIE_DEVICE_READY_NOTIFICATION, NULL);
if (!info)
return -EIO;
kfree(info);
return 0;
}
/**
* amdgpu_acpi_pcie_performance_request
*
* @adev: amdgpu_device pointer
* @perf_req: requested perf level (pcie gen speed)
* @advertise: set advertise caps flag if set
*
* Executes the PCIE_PERFORMANCE_REQUEST method to
* change the pcie gen speed (all asics).
* returns 0 on success, error on failure.
*/
int amdgpu_acpi_pcie_performance_request(struct amdgpu_device *adev,
u8 perf_req, bool advertise)
{
acpi_handle handle;
union acpi_object *info;
struct amdgpu_atcs *atcs = &adev->atcs;
struct atcs_pref_req_input atcs_input;
struct atcs_pref_req_output atcs_output;
struct acpi_buffer params;
size_t size;
u32 retry = 3;
if (amdgpu_acpi_pcie_notify_device_ready(adev))
return -EINVAL;
/* Get the device handle */
handle = ACPI_HANDLE(&adev->pdev->dev);
if (!handle)
return -EINVAL;
if (!atcs->functions.pcie_perf_req)
return -EINVAL;
atcs_input.size = sizeof(struct atcs_pref_req_input);
/* client id (bit 2-0: func num, 7-3: dev num, 15-8: bus num) */
atcs_input.client_id = adev->pdev->devfn | (adev->pdev->bus->number << 8);
atcs_input.valid_flags_mask = ATCS_VALID_FLAGS_MASK;
atcs_input.flags = ATCS_WAIT_FOR_COMPLETION;
if (advertise)
atcs_input.flags |= ATCS_ADVERTISE_CAPS;
atcs_input.req_type = ATCS_PCIE_LINK_SPEED;
atcs_input.perf_req = perf_req;
params.length = sizeof(struct atcs_pref_req_input);
params.pointer = &atcs_input;
while (retry--) {
info = amdgpu_atcs_call(handle, ATCS_FUNCTION_PCIE_PERFORMANCE_REQUEST, &params);
if (!info)
return -EIO;
memset(&atcs_output, 0, sizeof(atcs_output));
size = *(u16 *) info->buffer.pointer;
if (size < 3) {
DRM_INFO("ATCS buffer is too small: %zu\n", size);
kfree(info);
return -EINVAL;
}
size = min(sizeof(atcs_output), size);
memcpy(&atcs_output, info->buffer.pointer, size);
kfree(info);
switch (atcs_output.ret_val) {
case ATCS_REQUEST_REFUSED:
default:
return -EINVAL;
case ATCS_REQUEST_COMPLETE:
return 0;
case ATCS_REQUEST_IN_PROGRESS:
udelay(10);
break;
}
}
return 0;
}
/**
* amdgpu_acpi_event - handle notify events
*
* @nb: notifier block
* @val: val
* @data: acpi event
*
* Calls relevant amdgpu functions in response to various
* acpi events.
* Returns NOTIFY code
*/
static int amdgpu_acpi_event(struct notifier_block *nb,
unsigned long val,
void *data)
{
struct amdgpu_device *adev = container_of(nb, struct amdgpu_device, acpi_nb);
struct acpi_bus_event *entry = (struct acpi_bus_event *)data;
if (strcmp(entry->device_class, ACPI_AC_CLASS) == 0) {
if (power_supply_is_system_supplied() > 0)
DRM_DEBUG_DRIVER("pm: AC\n");
else
DRM_DEBUG_DRIVER("pm: DC\n");
amdgpu_pm_acpi_event_handler(adev);
}
/* Check for pending SBIOS requests */
return amdgpu_atif_handler(adev, entry);
}
/* Call all ACPI methods here */
/**
* amdgpu_acpi_init - init driver acpi support
*
* @adev: amdgpu_device pointer
*
* Verifies the AMD ACPI interfaces and registers with the acpi
* notifier chain (all asics).
* Returns 0 on success, error on failure.
*/
int amdgpu_acpi_init(struct amdgpu_device *adev)
{
acpi_handle handle;
struct amdgpu_atif *atif = &adev->atif;
struct amdgpu_atcs *atcs = &adev->atcs;
int ret;
/* Get the device handle */
handle = ACPI_HANDLE(&adev->pdev->dev);
if (!adev->bios || !handle)
return 0;
/* Call the ATCS method */
ret = amdgpu_atcs_verify_interface(handle, atcs);
if (ret) {
DRM_DEBUG_DRIVER("Call to ATCS verify_interface failed: %d\n", ret);
}
/* Call the ATIF method */
ret = amdgpu_atif_verify_interface(handle, atif);
if (ret) {
DRM_DEBUG_DRIVER("Call to ATIF verify_interface failed: %d\n", ret);
goto out;
}
if (atif->notifications.brightness_change) {
struct drm_encoder *tmp;
/* Find the encoder controlling the brightness */
list_for_each_entry(tmp, &adev->ddev->mode_config.encoder_list,
head) {
struct amdgpu_encoder *enc = to_amdgpu_encoder(tmp);
if ((enc->devices & (ATOM_DEVICE_LCD_SUPPORT)) &&
enc->enc_priv) {
struct amdgpu_encoder_atom_dig *dig = enc->enc_priv;
if (dig->bl_dev) {
atif->encoder_for_bl = enc;
break;
}
}
}
}
if (atif->functions.sbios_requests && !atif->functions.system_params) {
/* XXX check this workraround, if sbios request function is
* present we have to see how it's configured in the system
* params
*/
atif->functions.system_params = true;
}
if (atif->functions.system_params) {
ret = amdgpu_atif_get_notification_params(handle,
&atif->notification_cfg);
if (ret) {
DRM_DEBUG_DRIVER("Call to GET_SYSTEM_PARAMS failed: %d\n",
ret);
/* Disable notification */
atif->notification_cfg.enabled = false;
}
}
out:
adev->acpi_nb.notifier_call = amdgpu_acpi_event;
register_acpi_notifier(&adev->acpi_nb);
return ret;
}
/**
* amdgpu_acpi_fini - tear down driver acpi support
*
* @adev: amdgpu_device pointer
*
* Unregisters with the acpi notifier chain (all asics).
*/
void amdgpu_acpi_fini(struct amdgpu_device *adev)
{
unregister_acpi_notifier(&adev->acpi_nb);
}