Re: [PATCH net-next] net: phy: mscc: Add support for PHY LEDs on VSC8541

From: Andrew Lunn

Date: Thu Nov 06 2025 - 15:45:52 EST


> +static int vsc85xx_led_cntl_set_lock_unlock(struct phy_device *phydev,
> + u8 led_num,
> + u8 mode, bool lock)
> {
> int rc;
> u16 reg_val;
>
> - mutex_lock(&phydev->lock);
> + if (lock)
> + mutex_lock(&phydev->lock);
> reg_val = phy_read(phydev, MSCC_PHY_LED_MODE_SEL);
> reg_val &= ~LED_MODE_SEL_MASK(led_num);
> reg_val |= LED_MODE_SEL(led_num, (u16)mode);
> rc = phy_write(phydev, MSCC_PHY_LED_MODE_SEL, reg_val);
> - mutex_unlock(&phydev->lock);
> + if (lock)
> + mutex_unlock(&phydev->lock);
>
> return rc;
> }

The normal way to do this is have _vsc85xx_led_cntl_set() manipulate
the hardware, no locking. And have vsc85xx_led_cntl_set() take the
lock, call _vsc85xx_led_cntl_set(), and then release the lock. You can
then call _vsc85xx_led_cntl_set() if needed.

> +static int vsc8541_led_combine_disable_set(struct phy_device *phydev, u8 led_num,
> + bool combine_disable)
> +{
> + u16 reg_val;
> +
> + reg_val = phy_read(phydev, MSCC_PHY_LED_BEHAVIOR);

phy_read() can return a negative value. You should not assign that to
a u16.

Also, BEHAVIOUR.

> + reg_val &= ~LED_COMBINE_DIS_MASK(led_num);
> + reg_val |= LED_COMBINE_DIS(led_num, combine_disable);
> +
> + return phy_write(phydev, MSCC_PHY_LED_BEHAVIOR, reg_val);

You can probably use phy_modify() here.

> +static int vsc8541_led_hw_is_supported(struct phy_device *phydev, u8 index,
> + unsigned long rules)
> +{
> + struct vsc8531_private *vsc8531 = phydev->priv;
> + static const unsigned long supported = BIT(TRIGGER_NETDEV_LINK) |
> + BIT(TRIGGER_NETDEV_LINK_1000) |
> + BIT(TRIGGER_NETDEV_LINK_100) |
> + BIT(TRIGGER_NETDEV_LINK_10) |
> + BIT(TRIGGER_NETDEV_RX) |
> + BIT(TRIGGER_NETDEV_TX);
> +

Reverse Christmas tree. The lines should be sorted, longest first,
shortest last.

> +static int vsc8541_led_hw_control_get(struct phy_device *phydev, u8 index,
> + unsigned long *rules)
> +{
> + struct vsc8531_private *vsc8531 = phydev->priv;
> + u16 reg;
> +
> + if (index >= vsc8531->nleds)
> + return -EINVAL;
> +
> + reg = phy_read(phydev, MSCC_PHY_LED_MODE_SEL) & LED_MODE_SEL_MASK(index);

Another cause of u16, when int should be used. Please check all
instances of phy_read().

> + reg >>= LED_MODE_SEL_POS(index);
> + switch (reg) {
> + case VSC8531_LINK_ACTIVITY:
> + *rules = BIT(TRIGGER_NETDEV_LINK) |
> + BIT(TRIGGER_NETDEV_RX) |
> + BIT(TRIGGER_NETDEV_TX);
> + break;
> +
> + case VSC8531_LINK_1000_ACTIVITY:
> + *rules = BIT(TRIGGER_NETDEV_LINK) |
> + BIT(TRIGGER_NETDEV_LINK_1000) |
> + BIT(TRIGGER_NETDEV_RX) |
> + BIT(TRIGGER_NETDEV_TX);
> + break;
> +
> + case VSC8531_LINK_100_ACTIVITY:
> + *rules = BIT(TRIGGER_NETDEV_LINK) |
> + BIT(TRIGGER_NETDEV_LINK_100) |
> + BIT(TRIGGER_NETDEV_RX) |
> + BIT(TRIGGER_NETDEV_TX);
> + break;
> +
> + case VSC8531_LINK_10_ACTIVITY:
> + *rules = BIT(TRIGGER_NETDEV_LINK) |
> + BIT(TRIGGER_NETDEV_LINK_10) |
> + BIT(TRIGGER_NETDEV_RX) |
> + BIT(TRIGGER_NETDEV_TX);
> + break;
> +
> + case VSC8531_LINK_100_1000_ACTIVITY:
> + *rules = BIT(TRIGGER_NETDEV_LINK) |
> + BIT(TRIGGER_NETDEV_LINK_100) |
> + BIT(TRIGGER_NETDEV_LINK_1000) |
> + BIT(TRIGGER_NETDEV_RX) |
> + BIT(TRIGGER_NETDEV_TX);
> + break;
> +
> + case VSC8531_LINK_10_1000_ACTIVITY:
> + *rules = BIT(TRIGGER_NETDEV_LINK) |
> + BIT(TRIGGER_NETDEV_LINK_10) |
> + BIT(TRIGGER_NETDEV_LINK_1000) |
> + BIT(TRIGGER_NETDEV_RX) |
> + BIT(TRIGGER_NETDEV_TX);
> + break;
> +
> + case VSC8531_LINK_10_100_ACTIVITY:
> + *rules = BIT(TRIGGER_NETDEV_LINK) |
> + BIT(TRIGGER_NETDEV_LINK_10) |
> + BIT(TRIGGER_NETDEV_LINK_100) |
> + BIT(TRIGGER_NETDEV_RX) |
> + BIT(TRIGGER_NETDEV_TX);
> + break;
> +
> + case VSC8531_ACTIVITY:
> + *rules = BIT(TRIGGER_NETDEV_LINK) |
> + BIT(TRIGGER_NETDEV_RX) |
> + BIT(TRIGGER_NETDEV_TX);
> + break;

Should the combine bit be taken into account here?

> @@ -2343,6 +2532,26 @@ static int vsc85xx_probe(struct phy_device *phydev)
> if (!vsc8531->stats)
> return -ENOMEM;
>
> + phy_id = phydev->drv->phy_id & phydev->drv->phy_id_mask;
> + if (phy_id == PHY_ID_VSC8541) {

The VSC8541 has its own probe function, vsc8514_probe(). Why is this
needed?

Andrew

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