drm/nouveau: resurrect headless mode since rework

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_display.c

@@ -360,23 +360,26 @@ nouveau_display_create(struct drm_device *dev)
 	drm_kms_helper_poll_init(dev);
 	drm_kms_helper_poll_disable(dev);
 
-	if (nv_device(drm->device)->card_type < NV_50)
-		ret = nv04_display_create(dev);
-	else
-	if (nv_device(drm->device)->card_type < NV_D0)
-		ret = nv50_display_create(dev);
-	else
-		ret = nvd0_display_create(dev);
-	if (ret)
-		goto disp_create_err;
-
-	if (dev->mode_config.num_crtc) {
-		ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
+	if (nouveau_modeset == 1) {
+		if (nv_device(drm->device)->card_type < NV_50)
+			ret = nv04_display_create(dev);
+		else
+		if (nv_device(drm->device)->card_type < NV_D0)
+			ret = nv50_display_create(dev);
+		else
+			ret = nvd0_display_create(dev);
 		if (ret)
-			goto vblank_err;
+			goto disp_create_err;
+
+		if (dev->mode_config.num_crtc) {
+			ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
+			if (ret)
+				goto vblank_err;
+		}
+
+		nouveau_backlight_init(dev);
 	}
 
-	nouveau_backlight_init(dev);
 	return 0;
 
 vblank_err:
@@ -395,7 +398,8 @@ nouveau_display_destroy(struct drm_device *dev)
 	nouveau_backlight_exit(dev);
 	drm_vblank_cleanup(dev);
 
-	disp->dtor(dev);
+	if (disp->dtor)
+		disp->dtor(dev);
 
 	drm_kms_helper_poll_fini(dev);
 	drm_mode_config_cleanup(dev);

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -63,8 +63,9 @@ MODULE_PARM_DESC(noaccel, "disable kernel/abi16 acceleration");
 static int nouveau_noaccel = 0;
 module_param_named(noaccel, nouveau_noaccel, int, 0400);
 
-MODULE_PARM_DESC(modeset, "enable driver");
-static int nouveau_modeset = -1;
+MODULE_PARM_DESC(modeset, "enable driver (default: auto, "
+		          "0 = disabled, 1 = enabled, 2 = headless)");
+int nouveau_modeset = -1;
 module_param_named(modeset, nouveau_modeset, int, 0400);
 
 static struct drm_driver driver;
@@ -363,7 +364,8 @@ nouveau_drm_unload(struct drm_device *dev)
 
 	nouveau_pm_fini(dev);
 
-	nouveau_display_fini(dev);
+	if (dev->mode_config.num_crtc)
+		nouveau_display_fini(dev);
 	nouveau_display_destroy(dev);
 
 	nouveau_irq_fini(dev);
@@ -403,13 +405,15 @@ nouveau_drm_suspend(struct pci_dev *pdev, pm_message_t pm_state)
 	    pm_state.event == PM_EVENT_PRETHAW)
 		return 0;
 
-	NV_INFO(drm, "suspending fbcon...\n");
-	nouveau_fbcon_set_suspend(dev, 1);
+	if (dev->mode_config.num_crtc) {
+		NV_INFO(drm, "suspending fbcon...\n");
+		nouveau_fbcon_set_suspend(dev, 1);
 
-	NV_INFO(drm, "suspending display...\n");
-	ret = nouveau_display_suspend(dev);
-	if (ret)
-		return ret;
+		NV_INFO(drm, "suspending display...\n");
+		ret = nouveau_display_suspend(dev);
+		if (ret)
+			return ret;
+	}
 
 	NV_INFO(drm, "evicting buffers...\n");
 	ttm_bo_evict_mm(&drm->ttm.bdev, TTM_PL_VRAM);
@@ -445,8 +449,10 @@ nouveau_drm_suspend(struct pci_dev *pdev, pm_message_t pm_state)
 		nouveau_client_init(&cli->base);
 	}
 
-	NV_INFO(drm, "resuming display...\n");
-	nouveau_display_resume(dev);
+	if (dev->mode_config.num_crtc) {
+		NV_INFO(drm, "resuming display...\n");
+		nouveau_display_resume(dev);
+	}
 	return ret;
 }
 
@@ -486,8 +492,10 @@ nouveau_drm_resume(struct pci_dev *pdev)
 	nouveau_irq_postinstall(dev);
 	nouveau_pm_resume(dev);
 
-	NV_INFO(drm, "resuming display...\n");
-	nouveau_display_resume(dev);
+	if (dev->mode_config.num_crtc) {
+		NV_INFO(drm, "resuming display...\n");
+		nouveau_display_resume(dev);
+	}
 	return 0;
 }
 

drivers/gpu/drm/nouveau/nouveau_drm.h

@@ -141,4 +141,6 @@ int nouveau_drm_resume(struct pci_dev *);
 		nv_info((cli), fmt, ##args);                                   \
 } while (0)
 
+extern int nouveau_modeset;
+
 #endif

drivers/gpu/drm/nouveau/nouveau_irq.c

@@ -61,13 +61,15 @@ nouveau_irq_handler(DRM_IRQ_ARGS)
 
 	nv_subdev(pmc)->intr(nv_subdev(pmc));
 
-	if (device->card_type >= NV_D0) {
-		if (nv_rd32(device, 0x000100) & 0x04000000)
-			nvd0_display_intr(dev);
-	} else
-	if (device->card_type >= NV_50) {
-		if (nv_rd32(device, 0x000100) & 0x04000000)
-			nv50_display_intr(dev);
+	if (dev->mode_config.num_crtc) {
+		if (device->card_type >= NV_D0) {
+			if (nv_rd32(device, 0x000100) & 0x04000000)
+				nvd0_display_intr(dev);
+		} else
+		if (device->card_type >= NV_50) {
+			if (nv_rd32(device, 0x000100) & 0x04000000)
+				nv50_display_intr(dev);
+		}
 	}
 
 	return IRQ_HANDLED;