From: Gerd Hoffmann <kraxel@redhat.com>
Date: Mon, 30 Mar 2015 10:50:50 +0000 (+0200)
Subject: drm_vblank_get: don't WARN_ON in case vblanks are not initialized
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=16e3247da7f71f8c31f4330f739f6192a00c8b51;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

drm_vblank_get: don't WARN_ON in case vblanks are not initialized

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 1967e7fc9805..dd3fd1259950 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -1056,6 +1056,9 @@ 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;