[PATCH] disable-display

[Chris Wilson]

---
 drivers/gpu/drm/i915/i915_drv.c          | 37 ++++++++++++++++++++----
 drivers/gpu/drm/i915/intel_device_info.c |  9 ++----
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 5dd7fc582e6f..20f67c118e54 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -689,16 +689,10 @@ static int i915_load_modeset_init(struct drm_device *dev)
 
 	intel_setup_overlay(dev_priv);
 
-	if (INTEL_INFO(dev_priv)->num_pipes == 0)
-		return 0;
-
 	ret = intel_fbdev_init(dev);
 	if (ret)
 		goto cleanup_gem;
 
-	/* Only enable hotplug handling once the fbdev is fully set up. */
-	intel_hpd_init(dev_priv);
-
 	return 0;
 
 cleanup_gem:
@@ -1225,6 +1219,9 @@ static void i915_driver_register(struct drm_i915_private *dev_priv)
 	i915_gem_shrinker_register(dev_priv);
 	i915_pmu_register(dev_priv);
 
+	/* Only enable hotplug handling once the fbdev is fully set up. */
+	intel_hpd_init(dev_priv);
+
 	/*
 	 * Notify a valid surface after modesetting,
 	 * when running inside a VM.
@@ -1366,6 +1363,15 @@ static void i915_driver_destroy(struct drm_i915_private *i915)
 	pci_set_drvdata(pdev, NULL);
 }
 
+static void disable_display(struct drm_i915_private *i915)
+{
+	drm_atomic_helper_shutdown(&i915->drm);
+
+	flush_workqueue(i915->modeset_wq);
+	flush_work(&i915->atomic_helper.free_work);
+	flush_scheduled_work();
+}
+
 /**
  * i915_driver_load - setup chip and create an initial config
  * @pdev: PCI device
@@ -1426,6 +1432,25 @@ int i915_driver_load(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ret < 0)
 		goto out_cleanup_hw;
 
+	/* 
+	 * After completing our HW probe; tear it all down again (at the
+	 * users request)!
+	 *
+	 * Along side the CRTCs and connectors, there is a medley of
+	 * auxiliary HW which control various powerwells and interact with
+	 * other state (such as the BIOS framebuffer occupying a portion
+	 * of reserved memory). If the user tells us to run without any
+	 * displays enabled, we still need to register all the display and
+	 * auxiliary HW in order to safely disable them.
+	 */
+	if (i915_modparams.disable_display) {
+		DRM_INFO("Display disabled (module parameter)\n");
+		disable_display(dev_priv);
+		/* XXX free all ununused resources */
+		drm_mode_config_cleanup(&dev_priv->drm);
+		mkwrite_device_info(dev_priv)->num_pipes = 0;
+	}
+
 	i915_driver_register(dev_priv);
 
 	intel_init_ipc(dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
index 0ef0c6448d53..e50ea5b2576b 100644
--- a/drivers/gpu/drm/i915/intel_device_info.c
+++ b/drivers/gpu/drm/i915/intel_device_info.c
@@ -776,12 +776,9 @@ void intel_device_info_runtime_init(struct intel_device_info *info)
 			info->num_sprites[pipe] = 1;
 	}
 
-	if (i915_modparams.disable_display) {
-		DRM_INFO("Display disabled (module parameter)\n");
-		info->num_pipes = 0;
-	} else if (info->num_pipes > 0 &&
-		   (IS_GEN7(dev_priv) || IS_GEN8(dev_priv)) &&
-		   HAS_PCH_SPLIT(dev_priv)) {
+	if (info->num_pipes > 0 &&
+	    (IS_GEN7(dev_priv) || IS_GEN8(dev_priv)) &&
+	    HAS_PCH_SPLIT(dev_priv)) {
 		u32 fuse_strap = I915_READ(FUSE_STRAP);
 		u32 sfuse_strap = I915_READ(SFUSE_STRAP);
 
-- 
2.19.0.rc2