[Intel-gfx] [PATCH v2] drm/i915: prevent crash with .disable_display parameter

[clinton.a.taylor at intel.com]

From: Clint Taylor <clinton.a.taylor at intel.com>

The .disable_display parameter was causing a fatal crash when fbdev
was dereferenced during driver init.

V1: protection in i915_drv.c
V2: Moved protection to intel_fbdev.c

Cc: Chris Wilson <chris at chris-wilson.co.uk>

Signed-off-by: Clint Taylor <clinton.a.taylor at intel.com>
---
 drivers/gpu/drm/i915/intel_fbdev.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index bdefa61..bb0e9bf 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -742,6 +742,9 @@ void intel_fbdev_initial_config_async(struct drm_device *dev)
 {
 	struct intel_fbdev *ifbdev = to_i915(dev)->fbdev;
 
+	if (!ifbdev)
+		return;
+
 	ifbdev->cookie = async_schedule(intel_fbdev_initial_config, ifbdev);
 }
 
-- 
1.7.9.5