On Fri, Jun 20, 2025 at 10:33:53AM +0200, Luca Ceresoli wrote:

Hello Anusha,

On Thu, 19 Jun 2025 14:15:53 -0500
Anusha Srivatsa [off-list ref] wrote:

quoted

Take the panel reference and put it back as required.
drm_panel_add() and drm_panel_remove() add a panel to
the global registry and removes a panel respectively.
Use get() and put() helpers to keep up with refcounting.

Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Anusha Srivatsa <redacted>

This patch is good.

I'd just point out that this must be applied only after all drivers
have been converted to the the _alloc API, otherwise with the following
sequence:

  panel = devm_kzalloc();
  drm_panel_init(panel);
  drm_panel_add(panel);
  ...
  drm_panel_remove(panel); <-----

at the drm_panel_remove() you'd have a warning:

  refcount_t: addition on 0; use-after-free.

So, if all panel drivers are converted:

Not all panels are yet:
$ rg -l drm_panel_init -- drivers/gpu/drm/panel/ | wc -l
20

Maxime