Re: [PATCH net-next 4/4] net: dsa: realtek: add LED drivers for rtl8366rb

Simon Horman
2024-03-10T11:49:33Z

On Sun, Mar 10, 2024 at 01:52:01AM -0300, Luiz Angelo Daros de Luca wrote:
> This commit introduces LED drivers for rtl8366rb, enabling LEDs to be
> described in the device tree using the same format as qca8k. Each port
> can configure up to 4 LEDs.
>
> If all LEDs in a group use the default state "keep", they will use the
> default behavior after a reset. Changing the brightness of one LED,
> either manually or by a trigger, will disable the default hardware
> trigger and switch the entire LED group to manually controlled LEDs.
> Once in this mode, there is no way to revert to hardware-controlled LEDs
> (except by resetting the switch).
>
> Software triggers function as expected with manually controlled LEDs.
>
> Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> drivers/net/dsa/realtek/rtl8366rb.c | 270 ++++++++++++++++++++++++++++++++----

...

> +static int rtl8366rb_setup_led(struct realtek_priv *priv, struct dsa_port *dp,
> + struct fwnode_handle *led_fwnode)
> +{
> + struct rtl8366rb *rb = priv->chip_data;
> + struct led_init_data init_data = { };
> + struct rtl8366rb_led *led;
> + enum led_default_state state;
> + u32 led_group;
> + int ret;

nit: Please consider using reverse xmas tree - longest line to shortest -
for local variables in networking code.

...

> +static int rtl8366rb_setup_leds(struct realtek_priv *priv)
> +{
> + struct device_node *leds_np, *led_np;
> + struct dsa_switch *ds = &priv->ds;
> + struct dsa_port *dp;
> + int ret;
> +
> + dsa_switch_for_each_port(dp, ds) {
> + if (!dp->dn)
> + continue;
> +
> + leds_np = of_get_child_by_name(dp->dn, "leds");
> + if (!leds_np) {
> + dev_dbg(priv->dev, "No leds defined for port %d",
> + dp->index);
> + continue;
> + }
> +
> + for_each_child_of_node(leds_np, led_np) {
> + ret = rtl8366rb_setup_led(priv, dp,
> + of_fwnode_handle(led_np));
> + if (ret) {
> + of_node_put(led_np);

FWIIW, Coccinelle complans about "probable double put" here.
But it looks correct to me as it's only called when breaking out of
the loop, when it is required AFAIK.

> + break;
> + }
> + }
> +
> + of_node_put(leds_np);
> + if (ret)

I'm unsure if this can happen. But if for_each_child_of_node()
iterates zero times then ret may be uninitialised here.

Flagged by Smatch.

> + return ret;
> + }
> + return 0;
> +}

...