Merge tag 'drm-misc-next-2021-03-03' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for 5.13:

UAPI Changes:

Cross-subsystem Changes:

Core Changes:
  - %p4cc printk format modifier
  - atomic: introduce drm_crtc_commit_wait, rework atomic plane state
    helpers to take the drm_commit_state structure
  - dma-buf: heaps rework to return a struct dma_buf
  - simple-kms: Add plate state helpers
  - ttm: debugfs support, removal of sysfs

Driver Changes:
  - Convert drivers to shadow plane helpers
  - arc: Move to drm/tiny
  - ast: cursor plane reworks
  - gma500: Remove TTM and medfield support
  - mxsfb: imx8mm support
  - panfrost: MMU IRQ handling rework
  - qxl: rework to better handle resources deallocation, locking
  - sun4i: Add alpha properties for UI and VI layers
  - vc4: RPi4 CEC support
  - vmwgfx: doc cleanup

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210303100600.dgnkadonzuvfnu22@gilmour

1 files changed, 15 insertions, 59 deletions

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 22ce801e3a8d..1b4b64b71c7e 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -459,52 +459,6 @@ Contact: Emil Velikov, respective driver maintainers
 
 Level: Intermediate
 
-Plumb drm_atomic_state all over
--------------------------------
-
-Currently various atomic functions take just a single or a handful of
-object states (eg. plane state). While that single object state can
-suffice for some simple cases, we often have to dig out additional
-object states for dealing with various dependencies between the individual
-objects or the hardware they represent. The process of digging out the
-additional states is rather non-intuitive and error prone.
-
-To fix that most functions should rather take the overall
-drm_atomic_state as one of their parameters. The other parameters
-would generally be the object(s) we mainly want to interact with.
-
-For example, instead of
-
-.. code-block:: c
-
-   int (*atomic_check)(struct drm_plane *plane, struct drm_plane_state *state);
-
-we would have something like
-
-.. code-block:: c
-
-   int (*atomic_check)(struct drm_plane *plane, struct drm_atomic_state *state);
-
-The implementation can then trivially gain access to any required object
-state(s) via drm_atomic_get_plane_state(), drm_atomic_get_new_plane_state(),
-drm_atomic_get_old_plane_state(), and their equivalents for
-other object types.
-
-Additionally many drivers currently access the object->state pointer
-directly in their commit functions. That is not going to work if we
-eg. want to allow deeper commit pipelines as those pointers could
-then point to the states corresponding to a future commit instead of
-the current commit we're trying to process. Also non-blocking commits
-execute locklessly so there are serious concerns with dereferencing
-the object->state pointers without holding the locks that protect them.
-Use of drm_atomic_get_new_plane_state(), drm_atomic_get_old_plane_state(),
-etc. avoids these problems as well since they relate to a specific
-commit via the passed in drm_atomic_state.
-
-Contact: Ville Syrjälä, Daniel Vetter
-
-Level: Intermediate
-
 Use struct dma_buf_map throughout codebase
 ------------------------------------------
 
@@ -596,20 +550,24 @@ Contact: Daniel Vetter
 
 Level: Intermediate
 
-KMS cleanups
-------------
+Object lifetime fixes
+---------------------
+
+There's two related issues here
+
+- Cleanup up the various ->destroy callbacks, which often are all the same
+  simple code.
 
-Some of these date from the very introduction of KMS in 2008 ...
+- 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.
 
-- 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.
+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.
 
-- 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.
+Contact: Daniel Vetter
 
 Level: Intermediate
 
@@ -666,8 +624,6 @@ See the documentation of :ref:`VKMS <vkms>` for more details. This is an ideal
 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