[v2,0/4] drm/panel: Panel Refcounting infrastructure

Message

Anusha Srivatsa March 27, 2025, 2:55 p.m. UTC

This series adds the infrastructure needed for the refcounting
allocations for panels similar to Luca's efforts with bridges.
Underlying intention and idea is the same - avoid use-after-free
situations in panels. Get reference to panel when in use and put
the reference back (down) when not in use.
Once this gets approved, rest of the drivers will have to be
mass converted to use this API.  All the callers of of_drm_find_panel()
will have to be converted too.

Tried to split the patches as suggested in the RFC series[1].
Also fixed the connector used during panel_init to be the one
passed by driver.

Patch 4 was not suggested or part of my initial work. Added it
after looking at the comments Luca's v8 of the bridge series
received.[2]

[1] -> https://patchwork.freedesktop.org/series/146236/
[2] -> https://patchwork.freedesktop.org/series/146306/#rev2

Suggested-by: Maxime Ripard <[e-mail]>
Signed-off-by: Anusha Srivatsa <[e-mail]>
---
Changes in v2:
- Change drm_panel_put() to return void.
- Export drm_panel_get()/put()
- Code cleanups: add missing return documentation, improve documentation
  in commit logs. 
- Link to v1: https://lore.kernel.org/r/[e-mail]

---
Anusha Srivatsa (4):
      drm/panel: Add new helpers for refcounted panel allocatons
      drm/panel: Add refcount support
      drm/panel: deprecate old-style panel allocation
      drm/panel/panel-simple: Use the new allocation in place of devm_kzalloc()

 drivers/gpu/drm/drm_panel.c          | 92 +++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/panel/panel-simple.c |  9 ++--
 include/drm/drm_panel.h              | 37 +++++++++++++++
 3 files changed, 131 insertions(+), 7 deletions(-)
---
base-commit: c8ba07caaecc622a9922cda49f24790821af8a71
change-id: 20250324-b4-panel-refcounting-40ab56aa34f7

Best regards,