vga_switcheroo: Remove assumptions about registration/unregistration ordering

[deliverable/linux.git] / drivers / gpu / vga / vga_switcheroo.c

diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
index 5b3c7d135dc91c407fc9b2bf19b2e3e912ccfed5..e10ba3755dfa1cf46fd2e9c2cdc13656bc959a35 100644 (file)
--- 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)
 {
@@ -113,6 +98,37 @@ 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 +150,7 @@ 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();
        }