On 03/14/2018 01:16 PM, Heiner Kallweit wrote: > Currently the PHY is unconditionally resumed in mdio_bus_phy_suspend(). > In cases where the PHY was sleepinh before suspending or if somebody else > takes care of resuming later, this is not needed and wastes energy. > > Also start the state machine only if it's used by the driver (indicated > by the adjust_link callback being defined). > > Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com> > --- > drivers/net/phy/phy_device.c | 33 +++++++++++++++++++++++---------- > 1 file changed, 23 insertions(+), 10 deletions(-) > > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > index a5691536f..c6fd79758 100644 > --- a/drivers/net/phy/phy_device.c > +++ b/drivers/net/phy/phy_device.c > @@ -124,6 +124,18 @@ static bool phy_may_suspend(struct phy_device *phydev) > } > > #ifdef CONFIG_PM > + > +static bool mdio_bus_phy_needs_start(struct phy_device *phydev) > +{ > + bool start;
How about needs_start? This is uber nitpicking but it seems to be more in line with what is being tested for here. > + > + mutex_lock(&phydev->lock); > + start = phydev->state == PHY_UP && phydev->adjust_link; You probably need to add an || phydev->phy_link_change here because that is what PHYLINK uses, it does not register an adjust_link callback, but would likely expect similar semantics. Even better, introduce a helper function that tests for both to avoid possible issues... > + mutex_unlock(&phydev->lock); > + > + return start; > +} > + > static int mdio_bus_phy_suspend(struct device *dev) > { > struct phy_device *phydev = to_phy_device(dev); > @@ -142,25 +154,25 @@ static int mdio_bus_phy_suspend(struct device *dev) > static int mdio_bus_phy_resume(struct device *dev) > { > struct phy_device *phydev = to_phy_device(dev); > - int ret; > + int ret = 0; > > - ret = phy_resume(phydev); > - if (ret < 0) > - return ret; > + if (!phydev->attached_dev) > + return 0; > > - if (phydev->attached_dev && phydev->adjust_link) > - phy_start_machine(phydev); > + if (mdio_bus_phy_needs_start(phydev)) > + phy_start(phydev); > + else if (!phydev->adjust_link) > + ret = phy_resume(phydev); Humm, under which conditions can you not have phydev->attached_dev and also not phydev->adjust_link being set? As mentioned earlier, you would likely need to test for phy_link_change too here. > > - return 0; > + return ret; > } > > static int mdio_bus_phy_restore(struct device *dev) > { > struct phy_device *phydev = to_phy_device(dev); > - struct net_device *netdev = phydev->attached_dev; > int ret; > > - if (!netdev) > + if (!phydev->attached_dev) > return 0; That does not seem to be making any functional difference, so I would just drop this for now. > > ret = phy_init_hw(phydev); > @@ -171,7 +183,8 @@ static int mdio_bus_phy_restore(struct device *dev) > phydev->link = 0; > phydev->state = PHY_UP; > > - phy_start_machine(phydev); > + if (mdio_bus_phy_needs_start(phydev)) > + phy_start(phydev); > > return 0; > } > -- Florian