On 05/23/2018 12:31 PM, Heiner Kallweit wrote:
> If the parent of the MDIO bus is runtime-suspended, we may not be able
> to access the MDIO bus. Therefore add a check for this situation.
>
> So far phy_suspend() only checks for WoL being enabled, other checks
> are in mdio_bus_phy_may_suspend(). Improve this and move all checks
> to a new function phy_may_suspend() and call it from phy_suspend().
>
> Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com>
> ---
> drivers/net/phy/phy_device.c | 33 +++++++++++++++++++++------------
> 1 file changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 1662781fb..e0a71e3e5 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -35,6 +35,7 @@
> #include <linux/io.h>
> #include <linux/uaccess.h>
> #include <linux/of.h>
> +#include <linux/pm_runtime.h>
>
> #include <asm/irq.h>
>
> @@ -75,14 +76,27 @@ extern struct phy_driver genphy_10g_driver;
> static LIST_HEAD(phy_fixup_list);
> static DEFINE_MUTEX(phy_fixup_lock);
>
> -#ifdef CONFIG_PM
> -static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
> +static bool phy_may_suspend(struct phy_device *phydev)
> {
> struct device_driver *drv = phydev->mdio.dev.driver;
> struct phy_driver *phydrv = to_phy_driver(drv);
> struct net_device *netdev = phydev->attached_dev;
> + struct device *mdio_bus_parent = phydev->mdio.bus->parent;
> + struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
> +
> + if (phydev->suspended || !drv || !phydrv->suspend)
> + return false;
> +
> + /* If the device has WOL enabled, we cannot suspend the PHY */
> + phy_ethtool_get_wol(phydev, &wol);
> + if (wol.wolopts)
> + return false;
phy_ethtool_get_wol() can created MDIO bus accesses so should not this
be moved after the check for the MDIO bus being runtime suspended?
>
> - if (!drv || !phydrv->suspend)
> + /* If the parent of the MDIO bus is runtime-suspended, the MDIO bus may
> + * not be accessible and we expect the parent to suspend all devices
> + * on the MDIO bus when it suspends.
> + */
> + if (mdio_bus_parent && pm_runtime_suspended(mdio_bus_parent))
> return false;
>
> /* PHY not attached? May suspend if the PHY has not already been
> @@ -91,7 +105,7 @@ static bool mdio_bus_phy_may_suspend(struct phy_device
> *phydev)
> * MDIO bus driver and clock gated at this point.
> */
> if (!netdev)
> - return !phydev->suspended;
> + return true;
>
> /* Don't suspend PHY if the attached netdev parent may wakeup.
> * The parent may point to a PCI device, as in tg3 driver.
> @@ -109,6 +123,7 @@ static bool mdio_bus_phy_may_suspend(struct phy_device
> *phydev)
> return true;
> }
>
> +#ifdef CONFIG_PM
> static int mdio_bus_phy_suspend(struct device *dev)
> {
> struct phy_device *phydev = to_phy_device(dev);
> @@ -121,9 +136,6 @@ static int mdio_bus_phy_suspend(struct device *dev)
> if (phydev->attached_dev && phydev->adjust_link)
> phy_stop_machine(phydev);
>
> - if (!mdio_bus_phy_may_suspend(phydev))
> - return 0;
Hummm why is it okay to drop that one?
> -
> return phy_suspend(phydev);
> }
>
> @@ -1162,13 +1174,10 @@ EXPORT_SYMBOL(phy_detach);
> int phy_suspend(struct phy_device *phydev)
> {
> struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
> - struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
> int ret = 0;
>
> - /* If the device has WOL enabled, we cannot suspend the PHY */
> - phy_ethtool_get_wol(phydev, &wol);
> - if (wol.wolopts)
> - return -EBUSY;
> + if (!phy_may_suspend(phydev))
> + return 0;
>
> if (phydev->drv && phydrv->suspend)
> ret = phydrv->suspend(phydev);
>
--
Florian
