Am 23.05.2018 um 21:43 schrieb Florian Fainelli:
> 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?
>
Good point. Yes, the WoL check needs to be moved.
>>
>> - 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?
>
All checks in mdio_bus_phy_may_suspend() have been moved to
phy_may_suspend() which is called from phy_suspend()
directly now.
>> -
>> 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);
>>
>
>
