Hi Dmitry,
On 10/19/2026 9:12 PM, Dmitry Baryshkov wrote:
> The writeback properties are created once per device and attached to
> every writeback connector. Nevertheless, a failing
> __drm_writeback_connector_init() destroys all three of them. If an
> earlier writeback connector has already been registered (komeda and
> rcar-du create one per CRTC), it is left holding stale property
> pointers. The drmm cleanup action likewise destroys them as soon as the
> first connector goes away.
>
> Leave the properties alone. They are on the device's property list, so
> drm_mode_config_cleanup() destroys them together with all other
> properties.
>
If a user attaches a private property to a connector, are they
responsible for calling put on that property during cleanup?
In that case, can drmm* functions be used to clean up these
properties? Thank you.
> Fixes: 2f3f4a73631b ("drm: writeback: Add missing cleanup in case of
> initialization failure")
> Assisted-by: LLM
> Signed-off-by: Dmitry Baryshkov <[email protected]>
> ---
> drivers/gpu/drm/drm_writeback.c | 34 ++++++----------------------------
> 1 file changed, 6 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
> index 89c36f1414ce..2f6a7b50336c 100644
> --- a/drivers/gpu/drm/drm_writeback.c
> +++ b/drivers/gpu/drm/drm_writeback.c
> @@ -148,22 +148,6 @@ static int create_writeback_properties(struct drm_device
> *dev)
> return 0;
> }
>
> -static void delete_writeback_properties(struct drm_device *dev)
> -{
> - if (dev->mode_config.writeback_pixel_formats_property) {
> - drm_property_destroy(dev,
> dev->mode_config.writeback_pixel_formats_property);
> - dev->mode_config.writeback_pixel_formats_property = NULL;
> - }
> - if (dev->mode_config.writeback_out_fence_ptr_property) {
> - drm_property_destroy(dev,
> dev->mode_config.writeback_out_fence_ptr_property);
> - dev->mode_config.writeback_out_fence_ptr_property = NULL;
> - }
> - if (dev->mode_config.writeback_fb_id_property) {
> - drm_property_destroy(dev,
> dev->mode_config.writeback_fb_id_property);
> - dev->mode_config.writeback_fb_id_property = NULL;
> - }
> -}
> -
> /**
> * __drm_writeback_connector_init - Initialize a writeback connector
> *
> @@ -198,20 +182,18 @@ static int __drm_writeback_connector_init(struct
> drm_device *dev,
> int ret = create_writeback_properties(dev);
>
> if (ret != 0)
> - goto failed_properties;
> + return ret;
>
> connector->interlace_allowed = 0;
>
> ret = drm_connector_attach_encoder(connector, enc);
> if (ret)
> - goto failed_properties;
> + return ret;
>
> blob = drm_property_create_blob(dev, n_formats * sizeof(*formats),
> formats);
> - if (IS_ERR(blob)) {
> - ret = PTR_ERR(blob);
> - goto failed_properties;
> - }
> + if (IS_ERR(blob))
> + return PTR_ERR(blob);
>
> INIT_LIST_HEAD(&wb_connector->job_queue);
> spin_lock_init(&wb_connector->job_lock);
> @@ -234,9 +216,6 @@ static int __drm_writeback_connector_init(struct
> drm_device *dev,
> wb_connector->pixel_formats_blob_ptr = blob;
>
> return 0;
> -failed_properties:
> - delete_writeback_properties(dev);
> - return ret;
> }
>
> /**
> @@ -295,8 +274,8 @@ EXPORT_SYMBOL(drm_writeback_connector_init);
> * @dev: DRM device
> * @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
> + * This will decrement the reference counter of blobs. 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,
> @@ -306,7 +285,6 @@ static void drm_writeback_connector_cleanup(struct
> drm_device *dev,
> 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);
>
> spin_lock_irqsave(&wb_connector->job_lock, flags);
>
--
Best,
Chaoyi
