phy_poll_reset(9) Safely wait until a PHY reset has properly completed


int phy_poll_reset(struct phy_device * phydev);



The PHY device to poll


According to IEEE 802.3, Section 2, Subsection, as published in 2008, a PHY reset may take up to 0.5 seconds. The MII BMCR register must be polled until the BMCR_RESET bit clears.

Furthermore, any attempts to write to PHY registers may have no effect or even generate MDIO bus errors until this is complete.

Some PHYs (such as the Marvell 88E1111) don't entirely conform to the standard and do not fully reset after the BMCR_RESET bit is set, and may even *REQUIRE* a soft-reset to properly restart autonegotiation. In an effort to support such broken PHYs, this function is separate from the standard phy_init_hw which will zero all the other bits in the BMCR and reapply all driver-specific and board-specific fixups.