[PATCH] drm/display: hdmi-cec-helper: Fix adapter unregistration
From: Cristian Ciocaltea
Date: Thu Jul 03 2025 - 16:06:25 EST
Attempting to reload a kernel module of an HDMI driver making use of the
new CEC helpers revealed a resource deallocation issue, i.e. the entries
in /dev/cec* keep growing.
Moreover, after a couple of tries the kernel crashes and the whole
system freezes:
[ 47.515950] Unable to handle kernel paging request at virtual address 0020072007200778
[...]
[ 47.521707] Internal error: Oops: 0000000096000004 [#1] SMP
[...]
[ 47.537597] Call trace:
[ 47.537815] klist_next+0x20/0x1b8 (P)
[ 47.538152] device_reorder_to_tail+0x74/0x120
[ 47.538548] device_reorder_to_tail+0x6c/0x120
[ 47.538944] device_pm_move_to_tail+0x78/0xd0
[ 47.539334] deferred_probe_work_func+0x9c/0x110
[ 47.539747] process_one_work+0x328/0x638
[ 47.540108] worker_thread+0x264/0x390
[ 47.540445] kthread+0x20c/0x230
[ 47.540735] ret_from_fork+0x10/0x20
Do a proper cleanup by calling cec_unregister_adapter() instead of
cec_delete_adapter() in the managed release action handler.
Fixes: 8b1a8f8b2002 ("drm/display: add CEC helpers code")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>
---
drivers/gpu/drm/display/drm_hdmi_cec_helper.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/display/drm_hdmi_cec_helper.c b/drivers/gpu/drm/display/drm_hdmi_cec_helper.c
index b4273c3522fa8b4996fd02107a87acefa3a45737..3651ad0f76e0c49cc7b3a8e2148dccb1f290e95a 100644
--- a/drivers/gpu/drm/display/drm_hdmi_cec_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_cec_helper.c
@@ -69,7 +69,7 @@ static void drm_connector_hdmi_cec_adapter_unregister(struct drm_device *dev, vo
struct drm_connector *connector = res;
struct drm_connector_hdmi_cec_data *data = connector->cec.data;
- cec_delete_adapter(data->adapter);
+ cec_unregister_adapter(data->adapter);
if (data->funcs->uninit)
data->funcs->uninit(connector);
---
base-commit: 8d6c58332c7a8ba025fcfa76888b6c37dbce9633
change-id: 20250703-hdmi-cec-helper-unreg-fix-d9e71349c1f4