phy_poll_reset — Safely wait until a PHY reset has properly completed
int phy_poll_reset ( | struct phy_device * phydev); |
According to IEEE 802.3, Section 2, Subsection 22.2.4.1.1, 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.