Revert "drm/amdgpu: disable runtime pm on PX laptops without dGPU power control"

BugLink: http://bugs.launchpad.net/bugs/1578798

commit e9bef455 upstream.

This reverts commit bedf2a65.

See the radeon revert for an extended description.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c

@@ -63,10 +63,6 @@ bool amdgpu_has_atpx(void) {
 	return amdgpu_atpx_priv.atpx_detected;
 }
 
-bool amdgpu_has_atpx_dgpu_power_cntl(void) {
-	return amdgpu_atpx_priv.atpx.functions.power_cntl;
-}
-
 /**
  * amdgpu_atpx_call - call an ATPX method
  *
@@ -146,6 +142,10 @@ static void amdgpu_atpx_parse_functions(struct amdgpu_atpx_functions *f, u32 mas
  */
 static int amdgpu_atpx_validate(struct amdgpu_atpx *atpx)
 {
+	/* make sure required functions are enabled */
+	/* dGPU power control is required */
+	atpx->functions.power_cntl = true;
+
 	if (atpx->functions.px_params) {
 		union acpi_object *info;
 		struct atpx_px_params output;

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -62,12 +62,6 @@ static const char *amdgpu_asic_name[] = {
 	"LAST",
 };
 
-#if defined(CONFIG_VGA_SWITCHEROO)
-bool amdgpu_has_atpx_dgpu_power_cntl(void);
-#else
-static inline bool amdgpu_has_atpx_dgpu_power_cntl(void) { return false; }
-#endif
-
 bool amdgpu_device_is_px(struct drm_device *dev)
 {
 	struct amdgpu_device *adev = dev->dev_private;
@@ -1517,7 +1511,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 
 	if (amdgpu_runtime_pm == 1)
 		runtime = true;
-	if (amdgpu_device_is_px(ddev) && amdgpu_has_atpx_dgpu_power_cntl())
+	if (amdgpu_device_is_px(ddev))
 		runtime = true;
 	vga_switcheroo_register_client(adev->pdev, &amdgpu_switcheroo_ops, runtime);
 	if (runtime)