[PATCH v4 1/1] drm/bridge: lt8912b: Fix issues found during static analysis

[Andrzej Hajda]

W dniu 31.03.2021 o 13:49, Adrien Grassein pisze:
> Some issues where found during static analysis of this driver.


Subject should describe what has been fixed, description why. If there 
is multiple different issues maybe patch split would be better.


>
> Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
> Suggested-by: Dan Carpenter  <dan.carpenter at oracle.com>
> Signed-off-by: Adrien Grassein <adrien.grassein at gmail.com>
> ---
>   drivers/gpu/drm/bridge/lontium-lt8912b.c | 27 +++++++++++++++---------
>   1 file changed, 17 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c
> index 61491615bad0..4c8d79142262 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c
> @@ -621,7 +621,8 @@ static int lt8912_parse_dt(struct lt8912 *lt)
>   {
>   	struct gpio_desc *gp_reset;
>   	struct device *dev = lt->dev;
> -	int ret = 0;
> +	int ret;
> +	int data_lanes;
>   	struct device_node *port_node;
>   	struct device_node *endpoint;
>   
> @@ -635,13 +636,16 @@ static int lt8912_parse_dt(struct lt8912 *lt)
>   	lt->gp_reset = gp_reset;
>   
>   	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
> -	if (IS_ERR(endpoint)) {
> -		ret = PTR_ERR(endpoint);
> -		goto end;
> -	}
> +	if (!endpoint)
> +		return -ENODEV;
>   
> -	lt->data_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
> +	data_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
>   	of_node_put(endpoint);
> +	if (data_lanes < 0) {
> +		dev_err(lt->dev, "%s: Bad data-lanes property\n", __func__);
> +		return data_lanes;
> +	}
> +	lt->data_lanes = data_lanes;
>   
>   	lt->host_node = of_graph_get_remote_node(dev->of_node, 0, -1);
>   	if (!lt->host_node) {
> @@ -658,19 +662,22 @@ static int lt8912_parse_dt(struct lt8912 *lt)
>   	}
>   
>   	lt->hdmi_port = of_drm_find_bridge(port_node);
> -	if (IS_ERR(lt->hdmi_port)) {
> +	if (!lt->hdmi_port) {
>   		dev_err(lt->dev, "%s: Failed to get hdmi port\n", __func__);
> -		ret = PTR_ERR(lt->hdmi_port);
> -		of_node_put(lt->host_node);
> -		goto end;
> +		ret = -ENODEV;
> +		of_node_put(port_node);
> +		goto err_free_host_node;
>   	}
>   
>   	if (!of_device_is_compatible(port_node, "hdmi-connector")) {
>   		dev_err(lt->dev, "%s: Failed to get hdmi port\n", __func__);
> +		of_node_put(port_node);
>   		ret = -EINVAL;
> +		goto err_free_host_node;

Maybe better would be to put of_node_put(port_node) after 
err_free_host_node label - of_node_put(NULL) does nothing.

>   	}
>   
>   	of_node_put(port_node);
> +	return 0;
>   
>   end:
>   	return ret;

This label and code can be removed, am I right?

After reading the body I know what the patch does, so I can propose the 
subject, what about "fix incorrect handling of of_* return values".

And please make description more descriptive :)

With that fixed you can add my:

Reviewed-by: Andrzej Hajda <a.hajda at samsung.com>

Regards
Andrzej