Various cleanups to the DRM core initialization and exit handlers:
- Register chrdev last: Once register_chrdev() returns, open() will succeed on the given chrdevs. This is usually not an issue, as no chardevs are registered, yet. However, nodes can be created by user-space via mknod(2), even though such major/minor combinations are unknown to the kernel. Avoid calling into drm_stub_open() in those cases. Again, drm_stub_open() would just bail out as the inode is unknown, but it's really non-obvious if you hack on drm_stub_open().
- Unify error-paths into just one label. All the error-path helpers can be called even though the constructors were not called yet, or failed. Hence, just call all cleanups unconditionally.
- Call into drm_global_release(). This is a no-op, but provides debugging helpers in case there're GLOBALS left on module unload. This function was unused until now.
- Use DRM_ERROR() instead of printk(), and also print the error-code on failure (even if it is static!).
- Don't throw away error-codes of register_chrdev()!
- Don't hardcode -1 as errno. This is just plain wrong.
- Order exit-handlers in the exact reverse order of initialization (except if the order actually matters for syncing-reasons, which is not the case here, though).
v2: - Call drm_core_exit() directly from the init-error-handler. Requires to drop __exit annotation, though.
Signed-off-by: David Herrmann dh.herrmann@gmail.com --- drivers/gpu/drm/drm_drv.c | 48 ++++++++++++++++++++++------------------------- 1 file changed, 22 insertions(+), 26 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index d771453..0773547 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -941,52 +941,48 @@ static const struct file_operations drm_stub_fops = { .llseek = noop_llseek, };
+static void drm_core_exit(void) +{ + unregister_chrdev(DRM_MAJOR, "drm"); + debugfs_remove(drm_debugfs_root); + drm_sysfs_destroy(); + idr_destroy(&drm_minors_idr); + drm_connector_ida_destroy(); + drm_global_release(); +} + static int __init drm_core_init(void) { - int ret = -ENOMEM; + int ret;
drm_global_init(); drm_connector_ida_init(); idr_init(&drm_minors_idr);
- if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops)) - goto err_p1; - ret = drm_sysfs_init(); if (ret < 0) { - printk(KERN_ERR "DRM: Error creating drm class.\n"); - goto err_p2; + DRM_ERROR("Cannot create DRM class: %d\n", ret); + goto error; }
drm_debugfs_root = debugfs_create_dir("dri", NULL); if (!drm_debugfs_root) { - DRM_ERROR("Cannot create /sys/kernel/debug/dri\n"); - ret = -1; - goto err_p3; + ret = -ENOMEM; + DRM_ERROR("Cannot create debugfs-root: %d\n", ret); + goto error; }
+ ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops); + if (ret < 0) + goto error; + DRM_INFO("Initialized\n"); return 0; -err_p3: - drm_sysfs_destroy(); -err_p2: - unregister_chrdev(DRM_MAJOR, "drm");
- idr_destroy(&drm_minors_idr); -err_p1: +error: + drm_core_exit(); return ret; }
-static void __exit drm_core_exit(void) -{ - debugfs_remove(drm_debugfs_root); - drm_sysfs_destroy(); - - unregister_chrdev(DRM_MAJOR, "drm"); - - drm_connector_ida_destroy(); - idr_destroy(&drm_minors_idr); -} - module_init(drm_core_init); module_exit(drm_core_exit);