attempt to clean up stub_register, register_chrdev isn't good enough to

    make the decision for multiple cards with one drm ..

diff --git a/linux-core/drm_stub.c b/linux-core/drm_stub.c
index 1426af0..1a524e5 100644 (file)
--- a/linux-core/drm_stub.c
+++ b/linux-core/drm_stub.c
@@ -159,9 +159,9 @@ static int DRM(stub_putminor)(int minor)
  * \param dev DRM device.
  * \return zero on success or a negative number on failure.
  *
- * Attempt to register the char device and get the foreign "drm" data. If
- * successful then another module already registered so gets the stub info,
- * otherwise use this module stub info and make it available for other modules.
+ * Attempt to gets inter module "drm" information. If we are first
+ * then register the character device and inter module information.
+ * Try and register, if we fail to register, backout previous work.
  *
  * Finally calls stub_info::info_register.
  */
@@ -173,12 +173,9 @@ int DRM(stub_register)(const char *name, struct file_operations *fops,
        int ret2;
 
        DRM_DEBUG("\n");
-       ret1 = register_chrdev(DRM_MAJOR, "drm", &DRM(stub_fops));
-       if (ret1 == -EBUSY) 
-               i = (struct drm_stub_info *)inter_module_get("drm");
-       if (ret1 < 0)
-               return -1;
-
+       /* use the inter_module_get to check - as if the same module
+          registers chrdev twice it succeeds */
+       i = (struct drm_stub_info *)inter_module_get("drm");
        if (i) {
                                /* Already registered */
                DRM(stub_info).info_register   = i->info_register;
@@ -187,6 +184,13 @@ int DRM(stub_register)(const char *name, struct file_operations *fops,
                DRM(stub_info).info_count = i->info_count;
                DRM_DEBUG("already registered\n");
        } else if (*DRM(stub_info).info_count == 0) {
+
+               ret1 = register_chrdev(DRM_MAJOR, "drm", &DRM(stub_fops));
+                if (ret1 < 0) {
+                 printk (KERN_ERR, "Error registering drm major number.\n");
+                 return ret1;
+               }
+               
                DRM(stub_info).drm_class = class_simple_create(THIS_MODULE, "drm");
                if (IS_ERR(DRM(stub_info).drm_class)) {
                         printk (KERN_ERR "Error creating drm class.\n");
@@ -196,15 +200,15 @@ int DRM(stub_register)(const char *name, struct file_operations *fops,
                DRM_DEBUG("calling inter_module_register\n");
                inter_module_register("drm", THIS_MODULE, &DRM(stub_info));
        }
+
        if (DRM(stub_info).info_register) {
                ret2 = DRM(stub_info).info_register(name, fops, dev);
                if (ret2) {
-                       if (!ret1) {
+                       if (!i) {
+                               inter_module_unregister("drm");
                                unregister_chrdev(DRM_MAJOR, "drm");
                                class_simple_destroy(DRM(stub_info).drm_class);
                        }
-                       if (!i)
-                               inter_module_unregister("drm");
                }
                return ret2;
        }

diff --git a/linux/drm_stub.h b/linux/drm_stub.h
index 1426af0..1a524e5 100644 (file)
--- a/linux/drm_stub.h
+++ b/linux/drm_stub.h
@@ -159,9 +159,9 @@ static int DRM(stub_putminor)(int minor)
  * \param dev DRM device.
  * \return zero on success or a negative number on failure.
  *
- * Attempt to register the char device and get the foreign "drm" data. If
- * successful then another module already registered so gets the stub info,
- * otherwise use this module stub info and make it available for other modules.
+ * Attempt to gets inter module "drm" information. If we are first
+ * then register the character device and inter module information.
+ * Try and register, if we fail to register, backout previous work.
  *
  * Finally calls stub_info::info_register.
  */
@@ -173,12 +173,9 @@ int DRM(stub_register)(const char *name, struct file_operations *fops,
        int ret2;
 
        DRM_DEBUG("\n");
-       ret1 = register_chrdev(DRM_MAJOR, "drm", &DRM(stub_fops));
-       if (ret1 == -EBUSY) 
-               i = (struct drm_stub_info *)inter_module_get("drm");
-       if (ret1 < 0)
-               return -1;
-
+       /* use the inter_module_get to check - as if the same module
+          registers chrdev twice it succeeds */
+       i = (struct drm_stub_info *)inter_module_get("drm");
        if (i) {
                                /* Already registered */
                DRM(stub_info).info_register   = i->info_register;
@@ -187,6 +184,13 @@ int DRM(stub_register)(const char *name, struct file_operations *fops,
                DRM(stub_info).info_count = i->info_count;
                DRM_DEBUG("already registered\n");
        } else if (*DRM(stub_info).info_count == 0) {
+
+               ret1 = register_chrdev(DRM_MAJOR, "drm", &DRM(stub_fops));
+                if (ret1 < 0) {
+                 printk (KERN_ERR, "Error registering drm major number.\n");
+                 return ret1;
+               }
+               
                DRM(stub_info).drm_class = class_simple_create(THIS_MODULE, "drm");
                if (IS_ERR(DRM(stub_info).drm_class)) {
                         printk (KERN_ERR "Error creating drm class.\n");
@@ -196,15 +200,15 @@ int DRM(stub_register)(const char *name, struct file_operations *fops,
                DRM_DEBUG("calling inter_module_register\n");
                inter_module_register("drm", THIS_MODULE, &DRM(stub_info));
        }
+
        if (DRM(stub_info).info_register) {
                ret2 = DRM(stub_info).info_register(name, fops, dev);
                if (ret2) {
-                       if (!ret1) {
+                       if (!i) {
+                               inter_module_unregister("drm");
                                unregister_chrdev(DRM_MAJOR, "drm");
                                class_simple_destroy(DRM(stub_info).drm_class);
                        }
-                       if (!i)
-                               inter_module_unregister("drm");
                }
                return ret2;
        }