drm/i915: disable all crtcs at suspend time

We need this to avoid confusing the hw state readout code with the cpt
pch plls at resume time: We'd read the new pipe state (which is
disabled), but still believe that we have a life pll connected to that
pipe (from before the suspend). Hence properly disable pipes to clear
out all the residual state.

This has the neat side-effect that we don't enable ports prematurely
by restoring bogus state from the saved register values.
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.c

@@ -470,6 +470,9 @@ static int i915_drm_freeze(struct drm_device *dev)
 				"GEM idle failed, resume might fail\n");
 			return error;
 		}
+
+		intel_modeset_disable(dev);
+
 		drm_irq_uninstall(dev);
 	}
 

drivers/gpu/drm/i915/intel_display.c

@@ -3545,6 +3545,16 @@ static void intel_crtc_disable(struct drm_crtc *crtc)
 	}
 }
 
+void intel_modeset_disable(struct drm_device *dev)
+{
+	struct drm_crtc *crtc;
+
+	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+		if (crtc->enabled)
+			intel_crtc_disable(crtc);
+	}
+}
+
 void intel_encoder_noop(struct drm_encoder *encoder)
 {
 }

drivers/gpu/drm/i915/intel_drv.h

@@ -446,6 +446,7 @@ struct intel_set_config {
 
 extern bool intel_set_mode(struct drm_crtc *crtc, struct drm_display_mode *mode,
 			   int x, int y, struct drm_framebuffer *old_fb);
+extern void intel_modeset_disable(struct drm_device *dev);
 extern void intel_crtc_load_lut(struct drm_crtc *crtc);
 extern void intel_crtc_update_dpms(struct drm_crtc *crtc);
 extern void intel_encoder_noop(struct drm_encoder *encoder);