drm_bridge_get and drm_bridge_put() do nothing when they are passed a NULL
pointer, and they do so since their initial addition in commit 30d1b37d4c02
("drm/bridge: add support for refcounting").This allows simpler code in various places when using these functions. However it's not documented, so it's not clear whether it is part of the API "contract" or just a current implementation detail that might change in the future. There is no visible reason to remove this NULL check, so document it, making it part of the contract, letting users count on it. Signed-off-by: Luca Ceresoli <[email protected]> --- Historical note: I thought this was documented from the beginning and realized it's not the case when someone proposed adding a 'if (bridge) drm_bridge_put(bridge)' to a driver [0]. Let's fix it now. [0] https://lore.kernel.org/lkml/[email protected]/ --- drivers/gpu/drm/drm_bridge.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 3b165a0d1e77..3108249a63cd 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -282,7 +282,7 @@ static void __drm_bridge_free(struct kref *kref) /** * drm_bridge_get - Acquire a bridge reference - * @bridge: DRM bridge + * @bridge: DRM bridge; if NULL this function does nothing * * This function increments the bridge's refcount. * @@ -300,7 +300,7 @@ EXPORT_SYMBOL(drm_bridge_get); /** * drm_bridge_put - Release a bridge reference - * @bridge: DRM bridge + * @bridge: DRM bridge; if NULL this function does nothing * * This function decrements the bridge's reference count and frees the * object if the reference count drops to zero. --- base-commit: a50007089e078a1b7a826559a02277b1601ee189 change-id: 20260129-drm-bridge-alloc-getput-document-null-check-a551e64b8fc1 Best regards, -- Luca Ceresoli <[email protected]>
