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
