drm/i915: force restore on lid open

There seem to be indeed some awkwards machines around, mostly those
without OpRegion support, where the firmware changes the display hw
state behind our backs when closing the lid.

This force-restore logic has been originally introduced in

commit c1c7af60
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Thu Sep 10 15:28:03 2009 -0700

    drm/i915: force mode set at lid open time

but after the modeset-rework we've disabled it in the vain hope that
it's no longer required:

commit 3b7a89fc
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Sep 17 22:27:21 2012 +0200

    drm/i915: fix OOPS in lid_notify

Alas, no.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=54677
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=57434Tested-by: Krzysztof Mazur <krzysiek@podlesie.net>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.c

@@ -564,7 +564,7 @@ static int __i915_drm_thaw(struct drm_device *dev)
 		mutex_unlock(&dev->struct_mutex);
 
 		intel_modeset_init_hw(dev);
-		intel_modeset_setup_hw_state(dev);
+		intel_modeset_setup_hw_state(dev, false);
 		drm_irq_install(dev);
 	}
 

drivers/gpu/drm/i915/i915_drv.h

@@ -1652,7 +1652,8 @@ extern void intel_modeset_init(struct drm_device *dev);
 extern void intel_modeset_gem_init(struct drm_device *dev);
 extern void intel_modeset_cleanup(struct drm_device *dev);
 extern int intel_modeset_vga_set_state(struct drm_device *dev, bool state);
-extern void intel_modeset_setup_hw_state(struct drm_device *dev);
+extern void intel_modeset_setup_hw_state(struct drm_device *dev,
+					 bool force_restore);
 extern bool intel_fbc_enabled(struct drm_device *dev);
 extern void intel_disable_fbc(struct drm_device *dev);
 extern bool ironlake_set_drps(struct drm_device *dev, u8 val);

drivers/gpu/drm/i915/intel_display.c

@@ -8988,7 +8988,8 @@ static void intel_sanitize_encoder(struct intel_encoder *encoder)
 
 /* Scan out the current hw modeset state, sanitizes it and maps it into the drm
  * and i915 state tracking structures. */
-void intel_modeset_setup_hw_state(struct drm_device *dev)
+void intel_modeset_setup_hw_state(struct drm_device *dev,
+				  bool force_restore)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	enum pipe pipe;
@@ -9087,7 +9088,15 @@ void intel_modeset_setup_hw_state(struct drm_device *dev)
 		intel_sanitize_crtc(crtc);
 	}
 
+	if (force_restore) {
+		for_each_pipe(pipe) {
+			crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
+			intel_set_mode(&crtc->base, &crtc->base.mode,
+				       crtc->base.x, crtc->base.y, crtc->base.fb);
+		}
+	} else {
 		intel_modeset_update_staged_output_state(dev);
+	}
 
 	intel_modeset_check_state(dev);
 
@@ -9100,7 +9109,7 @@ void intel_modeset_gem_init(struct drm_device *dev)
 
 	intel_setup_overlay(dev);
 
-	intel_modeset_setup_hw_state(dev);
+	intel_modeset_setup_hw_state(dev, false);
 }
 
 void intel_modeset_cleanup(struct drm_device *dev)

drivers/gpu/drm/i915/intel_lvds.c

@@ -532,7 +532,7 @@ static int intel_lid_notify(struct notifier_block *nb, unsigned long val,
 	dev_priv->modeset_on_lid = 0;
 
 	mutex_lock(&dev->mode_config.mutex);
-	intel_modeset_check_state(dev);
+	intel_modeset_setup_hw_state(dev, true);
 	mutex_unlock(&dev->mode_config.mutex);
 
 	return NOTIFY_OK;