Re: [PATCH net-next v4 7/8] dsa: mv88e6xxx: Create port/netdev LEDs

Vladimir Oltean
2024-04-10T23:45:44Z

Nitpick: title: net: dsa: mv88e6xxx

On Sat, Apr 06, 2024 at 03:13:34PM -0500, Andrew Lunn wrote:
> Make use of the helpers to add LEDs to the user ports when the port is
> setup. Also remove the LEDs when the port is destroyed to avoid any
> race conditions with users of /sys/class/leds and LED triggers after
> the driver has been removed.
>
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> ---
> drivers/net/dsa/mv88e6xxx/Kconfig | 1 +
> drivers/net/dsa/mv88e6xxx/chip.c | 119 +++++++++++++++++++++++++++++++++++++-
> drivers/net/dsa/mv88e6xxx/chip.h | 13 +++++
> 3 files changed, 132 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/dsa/mv88e6xxx/Kconfig b/drivers/net/dsa/mv88e6xxx/Kconfig
> index e3181d5471df..ded5c6b9132b 100644
> --- a/drivers/net/dsa/mv88e6xxx/Kconfig
> +++ b/drivers/net/dsa/mv88e6xxx/Kconfig
> @@ -5,6 +5,7 @@ config NET_DSA_MV88E6XXX
> select IRQ_DOMAIN
> select NET_DSA_TAG_EDSA
> select NET_DSA_TAG_DSA
> + select NETDEV_LEDS

Do we want mv88e6xxx to select NETDEV_LEDS, or also to be able to build
it without LED control?

If we want to select, do we always want drivers to select NETDEV_LEDS?
Maybe hide the help text from the NETDEV_LEDS option, make it invisible
to the user?

> help
> This driver adds support for most of the Marvell 88E6xxx models of
> Ethernet switch chips, except 88E6060.
> diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
> index 3d7e4aa9293a..4e4031f11088 100644
> --- a/drivers/net/dsa/mv88e6xxx/chip.c
> +++ b/drivers/net/dsa/mv88e6xxx/chip.c
> @@ -31,6 +31,7 @@
> #include <linux/gpio/consumer.h>
> #include <linux/phylink.h>
> #include <net/dsa.h>
> +#include <net/netdev_leds.h>
>
> #include "chip.h"
> #include "devlink.h"
> @@ -3129,6 +3130,105 @@ static int mv88e6xxx_switch_reset(struct mv88e6xxx_chip *chip)
> return mv88e6xxx_software_reset(chip);
> }
>
> +static int mv88e6xxx_led_brightness_set(struct net_device *ndev,
> + u8 led, enum led_brightness value)
> +{
> + struct dsa_port *dp = dsa_port_from_netdev(ndev);
> + struct mv88e6xxx_chip *chip = dp->ds->priv;
> + int port = dp->index;
> + int err;
> +
> + if (chip->info->ops->led_brightness_set) {
> + mv88e6xxx_reg_lock(chip);
> + err = chip->info->ops->led_brightness_set(chip, port, led,
> + value);
> + mv88e6xxx_reg_unlock(chip);
> + return err;
> + }
> + return -EOPNOTSUPP;

The opposite looks more natural, if (!ops) return -EOPNOTSUPP, followed
by the normal code with 1 level of indentation less.

Comment applicable to all netdev_leds_ops below.

> +}
> +
> static int mv88e6xxx_set_port_mode(struct mv88e6xxx_chip *chip, int port,
> enum mv88e6xxx_frame_mode frame,
> enum mv88e6xxx_egress_mode egress, u16 etype)
> @@ -4006,7 +4106,9 @@ static int mv88e6xxx_setup(struct dsa_switch *ds)
>
> static int mv88e6xxx_port_setup(struct dsa_switch *ds, int port)
> {
> + struct dsa_port *dp = dsa_to_port(ds, port);
> struct mv88e6xxx_chip *chip = ds->priv;
> + struct mv88e6xxx_port *p;
> int err;
>
> if (chip->info->ops->pcs_ops &&
> @@ -4016,13 +4118,28 @@ static int mv88e6xxx_port_setup(struct dsa_switch *ds, int port)
> return err;
> }
>
> - return mv88e6xxx_setup_devlink_regions_port(ds, port);

Unfortunate, but there is an existing bug here. chip->info->ops->pcs_ops->pcs_init()
allocates memory. If mv88e6xxx_setup_devlink_regions_port() fails here,
that's memory we're not freeing, by not calling chip->info->ops->pcs_ops->pcs_teardown().

> + err = mv88e6xxx_setup_devlink_regions_port(ds, port);
> + if (err)
> + return err;
> +
> + if (dp->dn && dsa_is_user_port(ds, port)) {
> + p = &chip->ports[port];
> + INIT_LIST_HEAD(&p->leds);
> + err = netdev_leds_setup(dp->user, dp->dn, &p->leds,
> + &mv88e6xxx_netdev_leds_ops, 2);

Does anything bad happen with netdev_leds_setup() on platform_data?
OF APIs are pretty NULL-tolerant.

> + if (err)
> + mv88e6xxx_teardown_devlink_regions_port(ds, port);
> + }
> + return err;
> }
>
> static void mv88e6xxx_port_teardown(struct dsa_switch *ds, int port)
> {
> struct mv88e6xxx_chip *chip = ds->priv;
>
> + if (dsa_is_user_port(ds, port))
> + netdev_leds_teardown(&chip->ports[port].leds);

On platform_data, we are calling netdev_leds_teardown() when we never
called netdev_leds_setup() and never initialized the port leds list.

> +
> mv88e6xxx_teardown_devlink_regions_port(ds, port);
>
> if (chip->info->ops->pcs_ops &&
> diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
> index 64f8bde68ccf..d15bb5810831 100644
> --- a/drivers/net/dsa/mv88e6xxx/chip.h
> +++ b/drivers/net/dsa/mv88e6xxx/chip.h
> @@ -291,6 +291,9 @@ struct mv88e6xxx_port {
>
> /* MacAuth Bypass control flag */
> bool mab;
> +
> + /* LEDs associated to the port */
> + struct list_head leds;
> };
>
> enum mv88e6xxx_region_id {
> @@ -432,6 +435,7 @@ struct mv88e6xxx_chip {
>
> /* Bridge MST to SID mappings */
> struct list_head msts;
> +

Stray change.

> };
>
> struct mv88e6xxx_bus_ops {
> @@ -668,6 +672,15 @@ struct mv88e6xxx_ops {
> int (*led_blink_set)(struct mv88e6xxx_chip *chip, int port, u8 led,
> unsigned long *delay_on,
> unsigned long *delay_off);
> + int (*led_hw_control_is_supported)(struct mv88e6xxx_chip *chip,
> + int port, u8 led,
> + unsigned long flags);
> + int (*led_hw_control_set)(struct mv88e6xxx_chip *chip,
> + int port, u8 led,
> + unsigned long flags);
> + int (*led_hw_control_get)(struct mv88e6xxx_chip *chip,
> + int port, u8 led,
> + unsigned long *flags);
> };
>
> struct mv88e6xxx_irq_ops {
>
> --
> 2.43.0
>