drm: Cleanups after drmm_add_final_kfree rollout

A few things:
- Update the example driver in the documentation.
- We can drop the old kfree in drm_dev_release.
- Add a WARN_ON check in drm_dev_register to make sure everyone calls
  drmm_add_final_kfree and there's no leaks.

v2: Restore the full cleanup, I accidentally left some moved code
behind when fixing the bisectability of the series.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-20-daniel.vetter@ffwll.ch

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index b75cada..70d8975 100644 (file)
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -297,8 +297,6 @@ void drm_minor_release(struct drm_minor *minor)
  *
  *             drm_mode_config_cleanup(drm);
  *             drm_dev_fini(drm);
- *             kfree(priv->userspace_facing);
- *             kfree(priv);
  *     }
  *
  *     static struct drm_driver driver_drm_driver = {
@@ -326,10 +324,11 @@ void drm_minor_release(struct drm_minor *minor)
  *                     kfree(drm);
  *                     return ret;
  *             }
+ *             drmm_add_final_kfree(drm, priv);
  *
  *             drm_mode_config_init(drm);
  *
- *             priv->userspace_facing = kzalloc(..., GFP_KERNEL);
+ *             priv->userspace_facing = drmm_kzalloc(..., GFP_KERNEL);
  *             if (!priv->userspace_facing)
  *                     return -ENOMEM;
  *
@@ -837,10 +836,7 @@ static void drm_dev_release(struct kref *ref)
 
        drm_managed_release(dev);
 
-       if (!dev->driver->release && !dev->managed.final_kfree) {
-               WARN_ON(!list_empty(&dev->managed.resources));
-               kfree(dev);
-       } else if (dev->managed.final_kfree)
+       if (dev->managed.final_kfree)
                kfree(dev->managed.final_kfree);
 }
 
@@ -961,6 +957,8 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags)
        if (!driver->load)
                drm_mode_config_validate(dev);
 
+       WARN_ON(!dev->managed.final_kfree);
+
        if (drm_dev_needs_global_mutex(dev))
                mutex_lock(&drm_global_mutex);