[PATCH v3 3/4] drm_vblank_get: don't WARN_ON in case vblanks are not initialized

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/drm_irq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index af9662e..265793c 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -1029,6 +1029,9 @@ int drm_vblank_get(struct drm_device *dev, int crtc)
 	unsigned long irqflags;
 	int ret = 0;
 
+	if (!dev->num_crtcs)
+		return -EINVAL;
+
 	if (WARN_ON(crtc >= dev->num_crtcs))
 		return -EINVAL;
 
-- 
1.8.3.1