On 9/23/23 06:48, Vladimir Oltean wrote:
Some modules, like the MTIP AN/LT block used as a copper backplane PHY driver, need this extra information from the SerDes PHY as another source of "link up" information. Namely, the 25GBase-R PCS does not have a MDIO_CTRL1_LPOWER bit implemented in its MDIO_MMD_PCS:MDIO_CTRL1 register. That bit is typically set from phy_suspend() or phylink_pcs_disable() implementations, and that is supposed to cause a link drop event on the link partner. But here it does not happen. By implementing the networking phylink_pcs_disable() as phy_power_off(), we are able to actually power down the lane in a way that is visible to the remote end. Where it is visible is the CDR lock, so we introduce PHY_STATUS_TYPE_CDR_LOCK as an extra link indication, we are able to detect that condition and signal it to upper layers of the network stack. A more high-level and generic phy_get_status() operation was chosen instead of the more specific phy_get_cdr_lock() alternative, because I saw this as being more in the spirit of the generic PHY API. Also, phy_get_status() is more extensible and reusable for other purposes as well. Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx> -- Florian
