drm: Update todo.rst
Internship season is starting, let's review this. One thing that's
pending is Maxime's work to roll out drm_atomic_state pointers to all
callbacks, he said he'll remove that entry once it's all done.
v2: Fix typos (Maxime)
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210121112919.1460322-1-daniel.vetter@ffwll.ch
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 009d8e6..dea9082 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -577,20 +577,24 @@
Level: Intermediate
-KMS cleanups
-------------
+Object lifetime fixes
+---------------------
-Some of these date from the very introduction of KMS in 2008 ...
+There's two related issues here
-- Make ->funcs and ->helper_private vtables optional. There's a bunch of empty
- function tables in drivers, but before we can remove them we need to make sure
- that all the users in helpers and drivers do correctly check for a NULL
- vtable.
+- Cleanup up the various ->destroy callbacks, which often are all the same
+ simple code.
-- Cleanup up the various ->destroy callbacks. A lot of them just wrapt the
- drm_*_cleanup implementations and can be removed. Some tack a kfree() at the
- end, for which we could add drm_*_cleanup_kfree(). And then there's the (for
- historical reasons) misnamed drm_primary_helper_destroy() function.
+- Lots of drivers erroneously allocate DRM modeset objects using devm_kzalloc,
+ which results in use-after free issues on driver unload. This can be serious
+ trouble even for drivers for hardware integrated on the SoC due to
+ EPROBE_DEFERRED backoff.
+
+Both these problems can be solved by switching over to drmm_kzalloc(), and the
+various convenience wrappers provided, e.g. drmm_crtc_alloc_with_planes(),
+drmm_universal_plane_alloc(), ... and so on.
+
+Contact: Daniel Vetter
Level: Intermediate
@@ -626,8 +630,6 @@
internship task, since it only requires a virtual machine and can be sized to
fit the available time.
-Contact: Daniel Vetter
-
Level: See details
Backlight Refactoring