Re: [PATCH net-next v3 2/5] net: phy: Add support for the Maxio MAE0621A

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] net: phy: maxio: potential configuration loss from soft reset
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commit fe4e6c1e8992faa353fc23228a8b3ebe634a12dd
Author: Liu Changjie <liucj1228@outlook.com>

net: phy: Add support for the Maxio MAE0621A

This commit adds a new driver for the Maxio MAE0621A Gigabit Ethernet PHY.
It introduces exact PHY ID matching and an optional configuration to enable
a 125 MHz clock on the CLKOUT pin based on device properties.

> diff --git a/drivers/net/phy/maxio.c b/drivers/net/phy/maxio.c
> new file mode 100644
> index 0000000000000..d2cb238956460
> --- /dev/null
> +++ b/drivers/net/phy/maxio.c
[ ... ]
> +static int maxio_mae0621a_config_init(struct phy_device *phydev)
> +{
> +	struct maxio_priv *priv = phydev->priv;
> +	int ret;
> +
> +	if (!priv->clk_out_125m)
> +		return 0;
> +
> +	ret = phy_modify_paged_changed(phydev, MAXIO_MAE0621A_PHYCR2_PAGE,
> +				       MAXIO_MAE0621A_PHYCR2,
> +				       MAXIO_MAE0621A_CLKOUT_ENABLE |
> +				       MAXIO_MAE0621A_CLKOUT_125M,
> +				       MAXIO_MAE0621A_CLKOUT_ENABLE |
> +				       MAXIO_MAE0621A_CLKOUT_125M);
> +	if (ret <= 0)
> +		return ret;
> +
> +	return genphy_soft_reset(phydev);

[Severity: Medium]
Does this soft reset potentially clear the vendor-specific paged register
configuration that was just applied?

IEEE 802.3 Clause 22 states that BMCR_RESET resets control registers to
their default values. While some PHYs retain their paged vendor configurations
across a soft reset, others wipe all registers. If the MAE0621A PHY clears
vendor pages during a soft reset, the newly applied
MAXIO_MAE0621A_CLKOUT_125M configuration in maxio_mae0621a_config_init()
might be silently reverted to its default state.

Could you confirm if this specific hardware retains the PHYCR2 register state
after genphy_soft_reset()?

> +}

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Sashiko AI review · https://sashiko.dev/#/patchset/20260926225625.25969-1-andre.przywara@arm.com?part=2