On Wed, Jun 05, 2019 at 01:44:08AM +0300, Vladimir Oltean wrote: > You caught me. > > But even ignoring the NIC case, isn't the PHY state machine > inconsistent with itself? It is ok with callink phy_suspend upon > ndo_stop, but it won't call phy_suspend after phy_connect, when the > netdev is implicitly stopped?
The PHY state machine isn't inconsistent with itself, but it does have strange behaviour. When the PHY is attached, the PHY is resumed and the state machine is in PHY_READY state. If it goes through a start/stop cycle, the state machine transitions to PHY_HALTED and attempts to place the PHY into a low power state. So the PHY state is consistent with the state machine state (we don't end up in the same state but with the PHY in a different state.) What we do have is a difference between the PHY state (and state machine state) between the boot scenario, and the interface up/down scenario, the latter behaviour having been introduced by a commit back in 2013: net: phy: suspend phydev when going to HALTED When phydev is going to HALTED state, we can try to suspend it to safe more power. phy_suspend helper will check if PHY can be suspended, so just call it when entering HALTED state. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up