drm/i915/skl: Do not allow scaling when crtc is disabled.

This fixes a warning when the crtc is turned off. In that case fb
will be NULL, and crtc_clock will be 0. Because the crtc is no longer
active this is not a bug, and shouldn't trigger the WARN_ON.

Also remove handling a null crtc_state, with all transitional helpers
gone this can no longer happen.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448360945-5723-2-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f1598f7..9928ca4 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13850,7 +13850,7 @@ skl_max_scale(struct intel_crtc *intel_crtc, struct intel_crtc_state *crtc_state
        struct drm_i915_private *dev_priv;
        int crtc_clock, cdclk;
 
-       if (!intel_crtc || !crtc_state)
+       if (!intel_crtc || !crtc_state->base.enable)
                return DRM_PLANE_HELPER_NO_SCALING;
 
        dev = intel_crtc->base.dev;