On Fri, 23 Aug 2024 17:20:49 +0800
Jinjie Ruan <ruanjinjie@xxxxxxxxxx> wrote:
> Avoids the need for manual cleanup of_node_put() in early exits
> from the loop.
>
> Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
There is more to do here, and looking at the code, I'm far from
sure it isn't releasing references it never had.
> ---
> drivers/gpu/drm/rockchip/rockchip_lvds.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_lvds.c b/drivers/gpu/drm/rockchip/rockchip_lvds.c
> index 9a01aa450741..f5b3f18794dd 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_lvds.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_lvds.c
> @@ -548,7 +548,7 @@ static int rockchip_lvds_bind(struct device *dev, struct device *master,
> struct drm_encoder *encoder;
> struct drm_connector *connector;
> struct device_node *remote = NULL;
> - struct device_node *port, *endpoint;
Odd extra space before *port in original. Clean that up whilst here.
> + struct device_node *port;
Use __free(device_node) for *port as well.
So where the current asignment is.
struct device_node *port = of_graph_get_port_by_id(dev->of_node, 1);
> int ret = 0, child_count = 0;
> const char *name;
> u32 endpoint_id = 0;
> @@ -560,15 +560,13 @@ static int rockchip_lvds_bind(struct device *dev, struct device *master,
> "can't found port point, please init lvds panel port!\n");
> return -EINVAL;
> }
> - for_each_child_of_node(port, endpoint) {
> + for_each_child_of_node_scoped(port, endpoint) {
> child_count++;
> of_property_read_u32(endpoint, "reg", &endpoint_id);
> ret = drm_of_find_panel_or_bridge(dev->of_node, 1, endpoint_id,
> &lvds->panel, &lvds->bridge);
> - if (!ret) {
> - of_node_put(endpoint);
> + if (!ret)
> break;
This then can simply be
return dev_err_probe(dev, ret,
"failed to find pannel and bridge node\n");
> - }
Various other paths become direct returns as well.
> }
The later code with remote looks suspect as not obvious who got the reference that
is being put but assuming that is correct, it's another possible place for __free based
cleanup.
> if (!child_count) {
> DRM_DEV_ERROR(dev, "lvds port does not have any children\n");
