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@xxxxxxxxx>
---
Hey
This is based on top of
"[PATCH] drm: drop obsolete drm_core.h"
Should be trivial to rebase, though. Just a DRM_ERROR()-message conflict.
Thanks
David
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);
--
2.9.3
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