Re: [PATCH net v2 1/3] net: phy: smsc: Fix Auto-MDIX configuration when disabled by strap

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

Hi Oleksij,

On Thu,  3 Jul 2025 13:49:39 +0200
Oleksij Rempel <o.rempel@pengutronix.de> wrote:

> Correct the Auto-MDIX configuration to ensure userspace settings are
> respected when the feature is disabled by the AUTOMDIX_EN hardware strap.
> 
> The LAN9500 PHY allows its default MDI-X mode to be configured via a
> hardware strap. If this strap sets the default to "MDI-X off", the
> driver was previously unable to enable Auto-MDIX from userspace.
> 
> When handling the ETH_TP_MDI_AUTO case, the driver would set the
> SPECIAL_CTRL_STS_AMDIX_ENABLE_ bit but neglected to set the required
> SPECIAL_CTRL_STS_OVRRD_AMDIX_ bit. Without the override flag, the PHY
> falls back to its hardware strap default, ignoring the software request.
> 
> This patch corrects the behavior by also setting the override bit when
> enabling Auto-MDIX. This ensures that the userspace configuration takes
> precedence over the hardware strap, allowing Auto-MDIX to be enabled
> correctly in all scenarios.
> 
> Fixes: 05b35e7eb9a1 ("smsc95xx: add phylib support")
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> Cc: Andre Edich <andre.edich@microchip.com>

Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>

Maxime