[PATCH v2] drm: writeback: Fix drm_writeback_connector_cleanup signature

[Louis Chauvet]

The drm_writeback_connector_cleanup have the signature:

     static void drm_writeback_connector_cleanup(
		struct drm_device *dev,
		struct drm_writeback_connector *wb_connector)

But it is stored and used as a drmres_release_t

    typedef void (*drmres_release_t)(struct drm_device *dev, void *res);

While the current code is valid and does not produce any warning, the
CFI runtime check (CONFIG_CFI_CLANG) can fail because the function
signature is not the same as drmres_release_t.

In order to fix this, change the function signature to match what is
expected by drmres_release_t.

Fixes: 1914ba2b91ea ("drm: writeback: Create drmm variants for drm_writeback_connector initialization")

Suggested-by: Mark Yacoub <markyacoub at google.com>
Signed-off-by: Louis Chauvet <louis.chauvet at bootlin.com>
---
Changes in v2:
- Forgot to update the documentation
- Link to v1: https://lore.kernel.org/r/20250428-drm-fix-writeback-cleanup-v1-1-e4c723868b73@bootlin.com
---
 drivers/gpu/drm/drm_writeback.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
index edbeab88ff2b..d983ee85cf13 100644
--- a/drivers/gpu/drm/drm_writeback.c
+++ b/drivers/gpu/drm/drm_writeback.c
@@ -343,17 +343,18 @@ EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder);
 /**
  * drm_writeback_connector_cleanup - Cleanup the writeback connector
  * @dev: DRM device
- * @wb_connector: Pointer to the writeback connector to clean up
+ * @data: Pointer to the writeback connector to clean up
  *
  * This will decrement the reference counter of blobs and destroy properties. It
  * will also clean the remaining jobs in this writeback connector. Caution: This helper will not
  * clean up the attached encoder and the drm_connector.
  */
 static void drm_writeback_connector_cleanup(struct drm_device *dev,
-					    struct drm_writeback_connector *wb_connector)
+					    void *data)
 {
 	unsigned long flags;
 	struct drm_writeback_job *pos, *n;
+	struct drm_writeback_connector *wb_connector = data;
 
 	delete_writeback_properties(dev);
 	drm_property_blob_put(wb_connector->pixel_formats_blob_ptr);
@@ -405,7 +406,7 @@ int drmm_writeback_connector_init(struct drm_device *dev,
 	if (ret)
 		return ret;
 
-	ret = drmm_add_action_or_reset(dev, (void *)drm_writeback_connector_cleanup,
+	ret = drmm_add_action_or_reset(dev, drm_writeback_connector_cleanup,
 				       wb_connector);
 	if (ret)
 		return ret;

---
base-commit: a22e0051f9eb2281b181218d97f77cebc299310d
change-id: 20250428-drm-fix-writeback-cleanup-a1179f3b9691

Best regards,
-- 
Louis Chauvet <louis.chauvet at bootlin.com>