drm/amdgpu: clarify DC checks

There are several places where we don't want to check
if a particular asic could support DC, but rather, if
DC is enabled. Set a flag if DC is enabled and check
for that rather than if a device supports DC or not.

Acked-by: Christian König <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

···
 	struct work_struct		reset_work;
 
 	bool                            job_hang;
+	bool                            dc_enabled;
 };
 
 static inline struct amdgpu_device *drm_to_adev(struct drm_device *ddev)

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

···
 	struct amdgpu_atif *atif = &amdgpu_acpi_priv.atif;
 
 	if (atif->notifications.brightness_change) {
-		if (amdgpu_device_has_dc_support(adev)) {
+		if (adev->dc_enabled) {
 #if defined(CONFIG_DRM_AMD_DC)
 			struct amdgpu_display_manager *dm = &adev->dm;
 

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

···
 	amdgpu_ta_if_debugfs_init(adev);
 
 #if defined(CONFIG_DRM_AMD_DC)
-	if (amdgpu_device_has_dc_support(adev))
+	if (adev->dc_enabled)
 		dtn_debugfs_init(adev);
 #endif
 

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

···
 
 	amdgpu_ras_resume(adev);
 
-	/*
-	 * Most of the connector probing functions try to acquire runtime pm
-	 * refs to ensure that the GPU is powered on when connector polling is
-	 * performed. Since we're calling this from a runtime PM callback,
-	 * trying to acquire rpm refs will cause us to deadlock.
-	 *
-	 * Since we're guaranteed to be holding the rpm lock, it's safe to
-	 * temporarily disable the rpm helpers so this doesn't deadlock us.
-	 */
+	if (adev->mode_info.num_crtc) {
+		/*
+		 * Most of the connector probing functions try to acquire runtime pm
+		 * refs to ensure that the GPU is powered on when connector polling is
+		 * performed. Since we're calling this from a runtime PM callback,
+		 * trying to acquire rpm refs will cause us to deadlock.
+		 *
+		 * Since we're guaranteed to be holding the rpm lock, it's safe to
+		 * temporarily disable the rpm helpers so this doesn't deadlock us.
+		 */
 #ifdef CONFIG_PM
-	dev->dev->power.disable_depth++;
+		dev->dev->power.disable_depth++;
 #endif
-	if (!amdgpu_device_has_dc_support(adev))
-		drm_helper_hpd_irq_event(dev);
-	else
-		drm_kms_helper_hotplug_event(dev);
+		if (!adev->dc_enabled)
+			drm_helper_hpd_irq_event(dev);
+		else
+			drm_kms_helper_hotplug_event(dev);
 #ifdef CONFIG_PM
-	dev->dev->power.disable_depth--;
+		dev->dev->power.disable_depth--;
 #endif
+	}
 	adev->in_suspend = false;
 
 	if (amdgpu_acpi_smart_shift_update(dev, AMDGPU_SS_DEV_D0))

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

···
 	 */
 	if ((bo_flags & AMDGPU_GEM_CREATE_CPU_GTT_USWC) &&
 	    amdgpu_bo_support_uswc(bo_flags) &&
-	    amdgpu_device_has_dc_support(adev) &&
+	    adev->dc_enabled &&
 	    adev->mode_info.gpu_vm_support)
 		domain |= AMDGPU_GEM_DOMAIN_GTT;
 #endif
···
 					 "dither",
 					 amdgpu_dither_enum_list, sz);
 
-	if (amdgpu_device_has_dc_support(adev)) {
+	if (adev->dc_enabled) {
 		adev->mode_info.abm_level_property =
 			drm_property_create_range(adev_to_drm(adev), 0,
 						  "abm level", 0, 4);

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

···
 		if (ret)
 			return ret;
 
-		if (amdgpu_device_has_dc_support(adev)) {
+		if (adev->dc_enabled) {
 			struct drm_crtc *crtc;
 
 			drm_for_each_crtc(crtc, drm_dev) {

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

···
 		adev_to_drm(adev)->dev,
 		&dev_attr_s3_debug);
 #endif
+	adev->dc_enabled = true;
 
 	return 0;
 }

drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c

···
 	struct pp_hwmgr *hwmgr = handle;
 	struct amdgpu_device *adev = hwmgr->adev;
 
-	if (!amdgpu_device_has_dc_support(adev)) {
+	if (!adev->dc_enabled) {
 		amdgpu_dpm_get_active_displays(adev);
 		adev->pm.pm_display_cfg.num_display = adev->pm.dpm.new_active_crtc_count;
 		adev->pm.pm_display_cfg.vrefresh = amdgpu_dpm_get_vrefresh(adev);