4 files changed, 40 insertions, 29 deletions

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 23120c00a881..90e28081712d 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -22,6 +22,7 @@ menuconfig DRM
 config DRM_USB
 	tristate
 	depends on DRM
+	depends on USB_ARCH_HAS_HCD
 	select USB
 
 config DRM_KMS_HELPER
diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c
index fc841e87b343..26ebffebe710 100644
--- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
+++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
@@ -211,11 +211,6 @@ static int nouveau_dsm_power_state(enum vga_switcheroo_client_id id,
 	return nouveau_dsm_set_discrete_state(nouveau_dsm_priv.dhandle, state);
 }
 
-static int nouveau_dsm_init(void)
-{
-	return 0;
-}
-
 static int nouveau_dsm_get_client_id(struct pci_dev *pdev)
 {
 	/* easy option one - intel vendor ID means Integrated */
@@ -232,7 +227,6 @@ static int nouveau_dsm_get_client_id(struct pci_dev *pdev)
 static struct vga_switcheroo_handler nouveau_dsm_handler = {
 	.switchto = nouveau_dsm_switchto,
 	.power_state = nouveau_dsm_power_state,
-	.init = nouveau_dsm_init,
 	.get_client_id = nouveau_dsm_get_client_id,
 };
 
diff --git a/drivers/gpu/drm/udl/Kconfig b/drivers/gpu/drm/udl/Kconfig
index 0b5e096d39a6..56e0bf31d425 100644
--- a/drivers/gpu/drm/udl/Kconfig
+++ b/drivers/gpu/drm/udl/Kconfig
@@ -1,6 +1,7 @@
 config DRM_UDL
 	tristate "DisplayLink"
 	depends on DRM && EXPERIMENTAL
+	depends on USB_ARCH_HAS_HCD
 	select DRM_USB
 	select FB_SYS_FILLRECT
 	select FB_SYS_COPYAREA
diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
index 5b3c7d135dc9..e25cf31faab2 100644
--- a/drivers/gpu/vga/vga_switcheroo.c
+++ b/drivers/gpu/vga/vga_switcheroo.c
@@ -70,27 +70,12 @@ static struct vgasr_priv vgasr_priv = {
 	.clients = LIST_HEAD_INIT(vgasr_priv.clients),
 };
 
-int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
-{
-	mutex_lock(&vgasr_mutex);
-	if (vgasr_priv.handler) {
-		mutex_unlock(&vgasr_mutex);
-		return -EINVAL;
-	}
-
-	vgasr_priv.handler = handler;
-	mutex_unlock(&vgasr_mutex);
-	return 0;
-}
-EXPORT_SYMBOL(vga_switcheroo_register_handler);
-
-void vga_switcheroo_unregister_handler(void)
+static bool vga_switcheroo_ready(void)
 {
-	mutex_lock(&vgasr_mutex);
-	vgasr_priv.handler = NULL;
-	mutex_unlock(&vgasr_mutex);
+	/* we're ready if we get two clients + handler */
+	return !vgasr_priv.active &&
+	       vgasr_priv.registered_clients == 2 && vgasr_priv.handler;
 }
-EXPORT_SYMBOL(vga_switcheroo_unregister_handler);
 
 static void vga_switcheroo_enable(void)
 {
@@ -98,7 +83,8 @@ static void vga_switcheroo_enable(void)
 	struct vga_switcheroo_client *client;
 
 	/* call the handler to init */
-	vgasr_priv.handler->init();
+	if (vgasr_priv.handler->init)
+		vgasr_priv.handler->init();
 
 	list_for_each_entry(client, &vgasr_priv.clients, list) {
 		if (client->id != -1)
@@ -113,6 +99,37 @@ static void vga_switcheroo_enable(void)
 	vgasr_priv.active = true;
 }
 
+int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
+{
+	mutex_lock(&vgasr_mutex);
+	if (vgasr_priv.handler) {
+		mutex_unlock(&vgasr_mutex);
+		return -EINVAL;
+	}
+
+	vgasr_priv.handler = handler;
+	if (vga_switcheroo_ready()) {
+		printk(KERN_INFO "vga_switcheroo: enabled\n");
+		vga_switcheroo_enable();
+	}
+	mutex_unlock(&vgasr_mutex);
+	return 0;
+}
+EXPORT_SYMBOL(vga_switcheroo_register_handler);
+
+void vga_switcheroo_unregister_handler(void)
+{
+	mutex_lock(&vgasr_mutex);
+	vgasr_priv.handler = NULL;
+	if (vgasr_priv.active) {
+		pr_info("vga_switcheroo: disabled\n");
+		vga_switcheroo_debugfs_fini(&vgasr_priv);
+		vgasr_priv.active = false;
+	}
+	mutex_unlock(&vgasr_mutex);
+}
+EXPORT_SYMBOL(vga_switcheroo_unregister_handler);
+
 static int register_client(struct pci_dev *pdev,
 			   const struct vga_switcheroo_client_ops *ops,
 			   int id, bool active)
@@ -134,9 +151,7 @@ static int register_client(struct pci_dev *pdev,
 	if (client_is_vga(client))
 		vgasr_priv.registered_clients++;
 
-	/* if we get two clients + handler */
-	if (!vgasr_priv.active &&
-	    vgasr_priv.registered_clients == 2 && vgasr_priv.handler) {
+	if (vga_switcheroo_ready()) {
 		printk(KERN_INFO "vga_switcheroo: enabled\n");
 		vga_switcheroo_enable();
 	}