drm/i915: Don't dereference fb when disabling primary plane
During driver init we may not have a valid framebuffer for the primary
plane even though the plane is enabled due to failed BIOS fb takeover.
This means we have to avoid dereferencing the fb in
.update_primary_plane() when disabling the plane.
The introduction of the primary plane rotation in
commit d91a2cb8e5104233c02bbde539bd4ee455ec12ac
Author: Sonika Jindal <sonika.jindal@intel.com>
Date: Fri Aug 22 14:06:04 2014 +0530
drm/i915: Add 180 degree primary plane rotation support
caused a regression by trying to look up the pixel format before we can
be sure there's a valid fb available. This isn't entirely unsurprising
since the rotation patches originally predate the change to the primary
plane code that calls .update_primary_plane() also when disabling the
plane:
commit fdd508a6419217cce28213f3c9bd27c02a0d4c71
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Fri Aug 8 21:51:11 2014 +0300
drm/i915: Call .update_primary_plane in intel_{enable,
disable}_primary_hw_plane()
v2: Warn but don't blow up when trying to enable a plane w/o an fb (Chris)
Cc: Sonika Jindal <sonika.jindal@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index cbd1591..c95d423 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2388,15 +2388,13 @@
struct drm_device *dev = crtc->dev;
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
- struct drm_i915_gem_object *obj = intel_fb_obj(fb);
+ struct drm_i915_gem_object *obj;
int plane = intel_crtc->plane;
unsigned long linear_offset;
u32 dspcntr;
u32 reg = DSPCNTR(plane);
int pixel_size;
- pixel_size = drm_format_plane_cpp(fb->pixel_format, 0);
-
if (!intel_crtc->primary_enabled) {
I915_WRITE(reg, 0);
if (INTEL_INFO(dev)->gen >= 4)
@@ -2407,6 +2405,12 @@
return;
}
+ obj = intel_fb_obj(fb);
+ if (WARN_ON(obj == NULL))
+ return;
+
+ pixel_size = drm_format_plane_cpp(fb->pixel_format, 0);
+
dspcntr = DISPPLANE_GAMMA_ENABLE;
dspcntr |= DISPLAY_PLANE_ENABLE;
@@ -2510,15 +2514,13 @@
struct drm_device *dev = crtc->dev;
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
- struct drm_i915_gem_object *obj = intel_fb_obj(fb);
+ struct drm_i915_gem_object *obj;
int plane = intel_crtc->plane;
unsigned long linear_offset;
u32 dspcntr;
u32 reg = DSPCNTR(plane);
int pixel_size;
- pixel_size = drm_format_plane_cpp(fb->pixel_format, 0);
-
if (!intel_crtc->primary_enabled) {
I915_WRITE(reg, 0);
I915_WRITE(DSPSURF(plane), 0);
@@ -2526,6 +2528,12 @@
return;
}
+ obj = intel_fb_obj(fb);
+ if (WARN_ON(obj == NULL))
+ return;
+
+ pixel_size = drm_format_plane_cpp(fb->pixel_format, 0);
+
dspcntr = DISPPLANE_GAMMA_ENABLE;
dspcntr |= DISPLAY_PLANE_ENABLE;