On 09/24/2018 12:56 PM, Heiner Kallweit wrote:
> On 24.09.2018 20:21, Florian Fainelli wrote:
>> On 09/24/2018 11:11 AM, Heiner Kallweit wrote:
>>> Core of the problem is that phy_suspend() suspends the PHY when it
>>> should not because of WoL. phy_suspend() checks for WoL already, but
>>> this works only if the PHY driver handles WoL (what is rarely the case).
>>> Typically WoL is handled by the MAC driver.
>>>
>>> This patch uses new member wol_enabled of struct net_device as
>>> additional criteria in the check when not to suspend the PHY because
>>> of WoL.
>>>
>>> Last but not least change phy_detach() to call phy_suspend() before
>>> attached_dev is set to NULL. phy_suspend() accesses attached_dev
>>> when checking whether the MAC driver activated WoL.
>>
>> Looks fine to me, just a few nits/questions down below:
>>
>> Reviewed-by: Florian Fainelli <f.faine...@gmail.com>
>>
>>>
>>> Fixes: f1e911d5d0df ("r8169: add basic phylib support")
>>> Fixes: e8cfd9d6c772 ("net: phy: call state machine synchronously in
>>> phy_stop")
>>> Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com>
>>> ---
>>> drivers/net/phy/phy_device.c | 12 +++++++++---
>>> 1 file changed, 9 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
>>> index af64a9320..6c0195e53 100644
>>> --- a/drivers/net/phy/phy_device.c
>>> +++ b/drivers/net/phy/phy_device.c
>>> @@ -93,7 +93,12 @@ static bool mdio_bus_phy_may_suspend(struct phy_device
>>> *phydev)
>>> if (!netdev)
>>> return !phydev->suspended;
>>>
>>> - /* Don't suspend PHY if the attached netdev parent may wakeup.
>>> + if (netdev->wol_enabled)
>>> + return false;
>>> +
>>> + /* As lang as not all affected network drivers support the
>>> + * wol_enabled flag, let's check for hints that WoL is enabled.
>>
>> Typo: as long (sorry for being that nitpicky).
>>
>>> + * Don't suspend PHY if the attached netdev parent may wakeup.
>>> * The parent may point to a PCI device, as in tg3 driver.
>>> */
>>> if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
>>> @@ -1132,9 +1137,9 @@ void phy_detach(struct phy_device *phydev)
>>> sysfs_remove_link(&dev->dev.kobj, "phydev");
>>> sysfs_remove_link(&phydev->mdio.dev.kobj, "attached_dev");
>>> }
>>> + phy_suspend(phydev);
>>> phydev->attached_dev->phydev = NULL;
>>> phydev->attached_dev = NULL;
>>> - phy_suspend(phydev);
>>> phydev->phylink = NULL;
>>>
>>> phy_led_triggers_unregister(phydev);
>>> @@ -1168,12 +1173,13 @@ EXPORT_SYMBOL(phy_detach);
>>> int phy_suspend(struct phy_device *phydev)
>>> {
>>> struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
>>> + struct net_device *netdev = phydev->attached_dev;
>>> 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)
>>> + if (wol.wolopts || (netdev && netdev->wol_enabled))
>>
>> Since you moved the phydev->attached_dev assignment to be after
>> phy_suspend(), do you really need to check for netdev here? Is there
>> another code path you found that might be running phy_suspend() with a
>> disconnected PHY? Not a problem per-se, just wondering.
>>
> There's a call to phy_suspend() in the phylib state machine and I'm
> not sure we can guarantee that a netdevice is attached.
> Because phy_suspend() is exported anybody can use it, correct or
> incorrect. Therefore I'd say core functions better should play safe.
Sounds good to me, better safe than sorry.
--
Florian
