Merge tag 'drm-vc4-fixes-2016-06-06' of github.com:anholt/linux into drm-fixes

This pull request brings in vblank/pageflip fixes I had hoped to see
merged before 4.7rc1, plus two new fixes that have come in since then.

* tag 'drm-vc4-fixes-2016-06-06' of github.com:anholt/linux:
  drm/vc4: Make pageflip completion handling more robust.
  drm/vc4: Fix ioctl permissions for render nodes.
  drm/vc4: Return -EBUSY if there's already a pending flip event.
  drm/vc4: Fix drm_vblank_put/get imbalance in page flip path.
  drm/vc4: Fix get_vblank_counter with proper no-op for Linux 4.4+

drivers/gpu/drm/vc4/vc4_crtc.c

@@ -456,14 +456,6 @@ static void vc4_crtc_atomic_flush(struct drm_crtc *crtc,
 
 	WARN_ON_ONCE(dlist_next - dlist_start != vc4_state->mm.size);
 
-	HVS_WRITE(SCALER_DISPLISTX(vc4_crtc->channel),
-		  vc4_state->mm.start);
-
-	if (debug_dump_regs) {
-		DRM_INFO("CRTC %d HVS after:\n", drm_crtc_index(crtc));
-		vc4_hvs_dump_state(dev);
-	}
-
 	if (crtc->state->event) {
 		unsigned long flags;
 
@@ -473,8 +465,20 @@ static void vc4_crtc_atomic_flush(struct drm_crtc *crtc,
 
 		spin_lock_irqsave(&dev->event_lock, flags);
 		vc4_crtc->event = crtc->state->event;
-		spin_unlock_irqrestore(&dev->event_lock, flags);
 		crtc->state->event = NULL;
+
+		HVS_WRITE(SCALER_DISPLISTX(vc4_crtc->channel),
+			  vc4_state->mm.start);
+
+		spin_unlock_irqrestore(&dev->event_lock, flags);
+	} else {
+		HVS_WRITE(SCALER_DISPLISTX(vc4_crtc->channel),
+			  vc4_state->mm.start);
+	}
+
+	if (debug_dump_regs) {
+		DRM_INFO("CRTC %d HVS after:\n", drm_crtc_index(crtc));
+		vc4_hvs_dump_state(dev);
 	}
 }
 
@@ -500,12 +504,17 @@ static void vc4_crtc_handle_page_flip(struct vc4_crtc *vc4_crtc)
 {
 	struct drm_crtc *crtc = &vc4_crtc->base;
 	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
+	u32 chan = vc4_crtc->channel;
 	unsigned long flags;
 
 	spin_lock_irqsave(&dev->event_lock, flags);
-	if (vc4_crtc->event) {
+	if (vc4_crtc->event &&
+	    (vc4_state->mm.start == HVS_READ(SCALER_DISPLACTX(chan)))) {
 		drm_crtc_send_vblank_event(crtc, vc4_crtc->event);
 		vc4_crtc->event = NULL;
+		drm_crtc_vblank_put(crtc);
 	}
 	spin_unlock_irqrestore(&dev->event_lock, flags);
 }
@@ -556,6 +565,7 @@ vc4_async_page_flip_complete(struct vc4_seqno_cb *cb)
 		spin_unlock_irqrestore(&dev->event_lock, flags);
 	}
 
+	drm_crtc_vblank_put(crtc);
 	drm_framebuffer_unreference(flip_state->fb);
 	kfree(flip_state);
 
@@ -598,6 +608,8 @@ static int vc4_async_page_flip(struct drm_crtc *crtc,
 		return ret;
 	}
 
+	WARN_ON(drm_crtc_vblank_get(crtc) != 0);
+
 	/* Immediately update the plane's legacy fb pointer, so that later
 	 * modeset prep sees the state that will be present when the semaphore
 	 * is released.

drivers/gpu/drm/vc4/vc4_drv.c

@@ -66,12 +66,12 @@ static const struct file_operations vc4_drm_fops = {
 };
 
 static const struct drm_ioctl_desc vc4_drm_ioctls[] = {
-	DRM_IOCTL_DEF_DRV(VC4_SUBMIT_CL, vc4_submit_cl_ioctl, 0),
-	DRM_IOCTL_DEF_DRV(VC4_WAIT_SEQNO, vc4_wait_seqno_ioctl, 0),
-	DRM_IOCTL_DEF_DRV(VC4_WAIT_BO, vc4_wait_bo_ioctl, 0),
-	DRM_IOCTL_DEF_DRV(VC4_CREATE_BO, vc4_create_bo_ioctl, 0),
-	DRM_IOCTL_DEF_DRV(VC4_MMAP_BO, vc4_mmap_bo_ioctl, 0),
-	DRM_IOCTL_DEF_DRV(VC4_CREATE_SHADER_BO, vc4_create_shader_bo_ioctl, 0),
+	DRM_IOCTL_DEF_DRV(VC4_SUBMIT_CL, vc4_submit_cl_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(VC4_WAIT_SEQNO, vc4_wait_seqno_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(VC4_WAIT_BO, vc4_wait_bo_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(VC4_CREATE_BO, vc4_create_bo_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(VC4_MMAP_BO, vc4_mmap_bo_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(VC4_CREATE_SHADER_BO, vc4_create_shader_bo_ioctl, DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(VC4_GET_HANG_STATE, vc4_get_hang_state_ioctl,
 			  DRM_ROOT_ONLY),
 };
@@ -91,7 +91,7 @@ static struct drm_driver vc4_drm_driver = {
 
 	.enable_vblank = vc4_enable_vblank,
 	.disable_vblank = vc4_disable_vblank,
-	.get_vblank_counter = drm_vblank_count,
+	.get_vblank_counter = drm_vblank_no_hw_counter,
 
 #if defined(CONFIG_DEBUG_FS)
 	.debugfs_init = vc4_debugfs_init,

drivers/gpu/drm/vc4/vc4_kms.c

@@ -117,10 +117,18 @@ static int vc4_atomic_commit(struct drm_device *dev,
 		return -ENOMEM;
 
 	/* Make sure that any outstanding modesets have finished. */
-	ret = down_interruptible(&vc4->async_modeset);
-	if (ret) {
-		kfree(c);
-		return ret;
+	if (nonblock) {
+		ret = down_trylock(&vc4->async_modeset);
+		if (ret) {
+			kfree(c);
+			return -EBUSY;
+		}
+	} else {
+		ret = down_interruptible(&vc4->async_modeset);
+		if (ret) {
+			kfree(c);
+			return ret;
+		}
 	}
 
 	ret = drm_atomic_helper_prepare_planes(dev, state);

drivers/gpu/drm/vc4/vc4_regs.h

@@ -341,6 +341,10 @@
 #define SCALER_DISPLACT0                        0x00000030
 #define SCALER_DISPLACT1                        0x00000034
 #define SCALER_DISPLACT2                        0x00000038
+#define SCALER_DISPLACTX(x)			(SCALER_DISPLACT0 +	\
+						 (x) * (SCALER_DISPLACT1 - \
+							SCALER_DISPLACT0))
+
 #define SCALER_DISPCTRL0                        0x00000040
 # define SCALER_DISPCTRLX_ENABLE		BIT(31)
 # define SCALER_DISPCTRLX_RESET			BIT(30)