drm/i915: WARN when trying to enabled an unused crtc
This is the first tiny step towards cross-checking the entire modeset
state machine with WARNs. A crtc can only be enabled when it's
actually in use, i.e. crtc->active imlies crtc->enabled.
Unfortunately we can't (yet) check this when disabling the crtc,
because the crtc helpers are a bit slopy with updating state and
unconditionally update crtc->enabled before changing the hw state.
Fixing that requires quite some more work.
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 673e8d4..36991dee 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -158,7 +158,15 @@
enum plane plane;
u8 lut_r[256], lut_g[256], lut_b[256];
int dpms_mode;
- bool active; /* is the crtc on? independent of the dpms mode */
+ /*
+ * Whether the crtc and the connected output pipeline is active. Implies
+ * that crtc->enabled is set, i.e. the current mode configuration has
+ * some outputs connected to this crtc.
+ *
+ * Atm crtc->enabled is unconditionally updated _before_ the hw state is
+ * changed, hence we can only check this when enabling the crtc.
+ */
+ bool active;
bool primary_disabled; /* is the crtc obscured by a plane? */
bool lowfreq_avail;
struct intel_overlay *overlay;