drm/nouveau: make sure display hardware is reinitialised on runtime resume

Linus commit 05c63c2f modified the
runtime suspend/resume paths to skip over display-related tasks to
avoid locking issues on resume.

Unfortunately, this resulted in the display hardware being left in
a partially initialised state, preventing subsequent modesets from
completing.

This commit unifies the (many) suspend/resume paths, bringing back
display (and fbcon) handling in the runtime paths.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_display.c

@@ -550,14 +550,12 @@ nouveau_display_destroy(struct drm_device *dev)
 }
 
 int
-nouveau_display_suspend(struct drm_device *dev)
+nouveau_display_suspend(struct drm_device *dev, bool runtime)
 {
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct drm_crtc *crtc;
 
 	nouveau_display_fini(dev);
 
-	NV_INFO(drm, "unpinning framebuffer(s)...\n");
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		struct nouveau_framebuffer *nouveau_fb;
 
@@ -579,12 +577,13 @@ nouveau_display_suspend(struct drm_device *dev)
 }
 
 void
-nouveau_display_repin(struct drm_device *dev)
+nouveau_display_resume(struct drm_device *dev, bool runtime)
 {
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct drm_crtc *crtc;
-	int ret;
+	int ret, head;
 
+	/* re-pin fb/cursors */
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		struct nouveau_framebuffer *nouveau_fb;
 
@@ -606,13 +605,6 @@ nouveau_display_repin(struct drm_device *dev)
 		if (ret)
 			NV_ERROR(drm, "Could not pin/map cursor.\n");
 	}
-}
-
-void
-nouveau_display_resume(struct drm_device *dev)
-{
-	struct drm_crtc *crtc;
-	int head;
 
 	nouveau_display_init(dev);
 
@@ -627,6 +619,13 @@ nouveau_display_resume(struct drm_device *dev)
 	for (head = 0; head < dev->mode_config.num_crtc; head++)
 		drm_vblank_on(dev, head);
 
+	/* This should ensure we don't hit a locking problem when someone
+	 * wakes us up via a connector.  We should never go into suspend
+	 * while the display is on anyways.
+	 */
+	if (runtime)
+		return;
+
 	drm_helper_resume_force_mode(dev);
 
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {

drivers/gpu/drm/nouveau/nouveau_display.h

@@ -63,9 +63,8 @@ int  nouveau_display_create(struct drm_device *dev);
 void nouveau_display_destroy(struct drm_device *dev);
 int  nouveau_display_init(struct drm_device *dev);
 void nouveau_display_fini(struct drm_device *dev);
-int  nouveau_display_suspend(struct drm_device *dev);
-void nouveau_display_repin(struct drm_device *dev);
-void nouveau_display_resume(struct drm_device *dev);
+int  nouveau_display_suspend(struct drm_device *dev, bool runtime);
+void nouveau_display_resume(struct drm_device *dev, bool runtime);
 int  nouveau_display_vblank_enable(struct drm_device *, int);
 void nouveau_display_vblank_disable(struct drm_device *, int);
 int  nouveau_display_scanoutpos(struct drm_device *, int, unsigned int,

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -547,9 +547,11 @@ nouveau_do_suspend(struct drm_device *dev, bool runtime)
 	struct nouveau_cli *cli;
 	int ret;
 
-	if (dev->mode_config.num_crtc && !runtime) {
+	if (dev->mode_config.num_crtc) {
+		NV_INFO(drm, "suspending console...\n");
+		nouveau_fbcon_set_suspend(dev, 1);
 		NV_INFO(drm, "suspending display...\n");
-		ret = nouveau_display_suspend(dev);
+		ret = nouveau_display_suspend(dev, runtime);
 		if (ret)
 			return ret;
 	}
@@ -603,7 +605,7 @@ nouveau_do_suspend(struct drm_device *dev, bool runtime)
 fail_display:
 	if (dev->mode_config.num_crtc) {
 		NV_INFO(drm, "resuming display...\n");
-		nouveau_display_resume(dev);
+		nouveau_display_resume(dev, runtime);
 	}
 	return ret;
 }
@@ -618,9 +620,6 @@ int nouveau_pmops_suspend(struct device *dev)
 	    drm_dev->switch_power_state == DRM_SWITCH_POWER_DYNAMIC_OFF)
 		return 0;
 
-	if (drm_dev->mode_config.num_crtc)
-		nouveau_fbcon_set_suspend(drm_dev, 1);
-
 	ret = nouveau_do_suspend(drm_dev, false);
 	if (ret)
 		return ret;
@@ -633,7 +632,7 @@ int nouveau_pmops_suspend(struct device *dev)
 }
 
 static int
-nouveau_do_resume(struct drm_device *dev)
+nouveau_do_resume(struct drm_device *dev, bool runtime)
 {
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nouveau_cli *cli;
@@ -658,7 +657,9 @@ nouveau_do_resume(struct drm_device *dev)
 
 	if (dev->mode_config.num_crtc) {
 		NV_INFO(drm, "resuming display...\n");
-		nouveau_display_repin(dev);
+		nouveau_display_resume(dev, runtime);
+		NV_INFO(drm, "resuming console...\n");
+		nouveau_fbcon_set_suspend(dev, 0);
 	}
 
 	return 0;
@@ -681,47 +682,21 @@ int nouveau_pmops_resume(struct device *dev)
 		return ret;
 	pci_set_master(pdev);
 
-	ret = nouveau_do_resume(drm_dev);
-	if (ret)
-		return ret;
-
-	if (drm_dev->mode_config.num_crtc) {
-		nouveau_display_resume(drm_dev);
-		nouveau_fbcon_set_suspend(drm_dev, 0);
-	}
-
-	return 0;
+	return nouveau_do_resume(drm_dev, false);
 }
 
 static int nouveau_pmops_freeze(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct drm_device *drm_dev = pci_get_drvdata(pdev);
-	int ret;
-
-	if (drm_dev->mode_config.num_crtc)
-		nouveau_fbcon_set_suspend(drm_dev, 1);
-
-	ret = nouveau_do_suspend(drm_dev, false);
-	return ret;
+	return nouveau_do_suspend(drm_dev, false);
 }
 
 static int nouveau_pmops_thaw(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct drm_device *drm_dev = pci_get_drvdata(pdev);
-	int ret;
-
-	ret = nouveau_do_resume(drm_dev);
-	if (ret)
-		return ret;
-
-	if (drm_dev->mode_config.num_crtc) {
-		nouveau_display_resume(drm_dev);
-		nouveau_fbcon_set_suspend(drm_dev, 0);
-	}
-
-	return 0;
+	return nouveau_do_resume(drm_dev, false);
 }
 
 
@@ -977,7 +952,7 @@ static int nouveau_pmops_runtime_resume(struct device *dev)
 		return ret;
 	pci_set_master(pdev);
 
-	ret = nouveau_do_resume(drm_dev);
+	ret = nouveau_do_resume(drm_dev, true);
 	drm_kms_helper_poll_enable(drm_dev);
 	/* do magic */
 	nvif_mask(device, 0x88488, (1 << 25), (1 << 25));