| Message ID | 1543479131-14097-1-git-send-email-hayashi.kunihiko@socionext.com |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,net] net: phy: fix the issue that netif always links up after resuming | expand |
On 29.11.2018 09:12, Kunihiko Hayashi wrote: > Even though the link is down before entering hibernation, > there is an issue that the network interface always links up after resuming > from hibernation. > > The phydev->state is PHY_READY before enabling the network interface, so > the link is down. After resuming from hibernation, the phydev->state is > forcibly set to PHY_UP in mdio_bus_phy_restore(), and the link becomes up. > > This patch expects to solve the issue by changing phydev->state to PHY_UP > only when the link is up. > > Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> > --- > drivers/net/phy/phy_device.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > index ab33d17..d5bba0f 100644 > --- a/drivers/net/phy/phy_device.c > +++ b/drivers/net/phy/phy_device.c > @@ -309,8 +309,10 @@ static int mdio_bus_phy_restore(struct device *dev) > return ret; > > /* The PHY needs to renegotiate. */ > - phydev->link = 0; > - phydev->state = PHY_UP; > + if (phydev->link) { > + phydev->link = 0; > + phydev->state = PHY_UP; > + } > Thanks for reporting. I agree that it isn't right to unconditionally set PHY_UP, because we don't know whether the PHY was started before hibernation. However I don't think using phydev->link as criteria is right. Example would be: PHY was started before hibernation, but w/o link. In this case we want to set PHY_UP to start an aneg, because a cable may have been plugged in whilst system was sleeping. So I think, similar to phy_stop_machine, we should use state >= UP and state != HALTED as criteria, and also phy_start_machine() would need to be called only if this criteria is met. It may make sense to add a helper for checking whether PHY is in a started state (>=UP && !=HALTED), because we need this in more than one place. > phy_start_machine(phydev); > >
On 11/29/2018 2:47 PM, Heiner Kallweit wrote: > On 29.11.2018 09:12, Kunihiko Hayashi wrote: >> Even though the link is down before entering hibernation, >> there is an issue that the network interface always links up after resuming >> from hibernation. >> >> The phydev->state is PHY_READY before enabling the network interface, so >> the link is down. After resuming from hibernation, the phydev->state is >> forcibly set to PHY_UP in mdio_bus_phy_restore(), and the link becomes up. >> >> This patch expects to solve the issue by changing phydev->state to PHY_UP >> only when the link is up. >> >> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> >> --- >> drivers/net/phy/phy_device.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c >> index ab33d17..d5bba0f 100644 >> --- a/drivers/net/phy/phy_device.c >> +++ b/drivers/net/phy/phy_device.c >> @@ -309,8 +309,10 @@ static int mdio_bus_phy_restore(struct device *dev) >> return ret; >> >> /* The PHY needs to renegotiate. */ >> - phydev->link = 0; >> - phydev->state = PHY_UP; >> + if (phydev->link) { >> + phydev->link = 0; >> + phydev->state = PHY_UP; >> + } >> > Thanks for reporting. I agree that it isn't right to unconditionally set > PHY_UP, because we don't know whether the PHY was started before > hibernation. However I don't think using phydev->link as criteria is > right. Example would be: PHY was started before hibernation, but w/o link. > In this case we want to set PHY_UP to start an aneg, because a cable may > have been plugged in whilst system was sleeping. > > So I think, similar to phy_stop_machine, we should use state >= UP and > state != HALTED as criteria, and also phy_start_machine() would need to > be called only if this criteria is met. > > It may make sense to add a helper for checking whether PHY is in a > started state (>=UP && !=HALTED), because we need this in more than > one place. Agreed, that would make sense. -- Florian
Hi Heiner Florian, Thank you for your comments. On Thu, 29 Nov 2018 16:37:48 -0800 <f.fainelli@gmail.com> wrote: > > > On 11/29/2018 2:47 PM, Heiner Kallweit wrote: > > On 29.11.2018 09:12, Kunihiko Hayashi wrote: > >> Even though the link is down before entering hibernation, > >> there is an issue that the network interface always links up after resuming > >> from hibernation. > >> > >> The phydev->state is PHY_READY before enabling the network interface, so > >> the link is down. After resuming from hibernation, the phydev->state is > >> forcibly set to PHY_UP in mdio_bus_phy_restore(), and the link becomes up. > >> > >> This patch expects to solve the issue by changing phydev->state to PHY_UP > >> only when the link is up. > >> > >> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> > >> --- > >> drivers/net/phy/phy_device.c | 6 ++++-- > >> 1 file changed, 4 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > >> index ab33d17..d5bba0f 100644 > >> --- a/drivers/net/phy/phy_device.c > >> +++ b/drivers/net/phy/phy_device.c > >> @@ -309,8 +309,10 @@ static int mdio_bus_phy_restore(struct device *dev) > >> return ret; > >> > >> /* The PHY needs to renegotiate. */ > >> - phydev->link = 0; > >> - phydev->state = PHY_UP; > >> + if (phydev->link) { > >> + phydev->link = 0; > >> + phydev->state = PHY_UP; > >> + } > >> > > Thanks for reporting. I agree that it isn't right to unconditionally set > > PHY_UP, because we don't know whether the PHY was started before > > hibernation. However I don't think using phydev->link as criteria is > > right. Example would be: PHY was started before hibernation, but w/o link. > > In this case we want to set PHY_UP to start an aneg, because a cable may > > have been plugged in whilst system was sleeping. Indeed. I didn't consider the case that the PHY was started but a cable was unplugged before hibernation. > > So I think, similar to phy_stop_machine, we should use state >= UP and > > state != HALTED as criteria, and also phy_start_machine() would need to > > be called only if this criteria is met. > > > > It may make sense to add a helper for checking whether PHY is in a > > started state (>=UP && !=HALTED), because we need this in more than > > one place. > > Agreed, that would make sense. I agree, too. I'll try this in v2 patch that changes the PHY state to PHY_UP and calls phy_start_machine(), only when the PHY was started before hibernation. If I understand correctly, it will be like that: phydev->link = 0; if (phy_is_started(phydev)) { phydev->state = PHY_UP; phy_start_machine(phydev); } Thank you, --- Best Regards, Kunihiko Hayashi
On 30.11.2018 05:37, Kunihiko Hayashi wrote: > Hi Heiner Florian, > > Thank you for your comments. > > On Thu, 29 Nov 2018 16:37:48 -0800 <f.fainelli@gmail.com> wrote: > >> >> >> On 11/29/2018 2:47 PM, Heiner Kallweit wrote: >>> On 29.11.2018 09:12, Kunihiko Hayashi wrote: >>>> Even though the link is down before entering hibernation, >>>> there is an issue that the network interface always links up after resuming >>>> from hibernation. >>>> >>>> The phydev->state is PHY_READY before enabling the network interface, so >>>> the link is down. After resuming from hibernation, the phydev->state is >>>> forcibly set to PHY_UP in mdio_bus_phy_restore(), and the link becomes up. >>>> >>>> This patch expects to solve the issue by changing phydev->state to PHY_UP >>>> only when the link is up. >>>> >>>> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> >>>> --- >>>> drivers/net/phy/phy_device.c | 6 ++++-- >>>> 1 file changed, 4 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c >>>> index ab33d17..d5bba0f 100644 >>>> --- a/drivers/net/phy/phy_device.c >>>> +++ b/drivers/net/phy/phy_device.c >>>> @@ -309,8 +309,10 @@ static int mdio_bus_phy_restore(struct device *dev) >>>> return ret; >>>> >>>> /* The PHY needs to renegotiate. */ >>>> - phydev->link = 0; >>>> - phydev->state = PHY_UP; >>>> + if (phydev->link) { >>>> + phydev->link = 0; >>>> + phydev->state = PHY_UP; >>>> + } >>>> >>> Thanks for reporting. I agree that it isn't right to unconditionally set >>> PHY_UP, because we don't know whether the PHY was started before >>> hibernation. However I don't think using phydev->link as criteria is >>> right. Example would be: PHY was started before hibernation, but w/o link. >>> In this case we want to set PHY_UP to start an aneg, because a cable may >>> have been plugged in whilst system was sleeping. > > Indeed. I didn't consider the case that the PHY was started but a cable was > unplugged before hibernation. > >>> So I think, similar to phy_stop_machine, we should use state >= UP and >>> state != HALTED as criteria, and also phy_start_machine() would need to >>> be called only if this criteria is met. >>> >>> It may make sense to add a helper for checking whether PHY is in a >>> started state (>=UP && !=HALTED), because we need this in more than >>> one place. >> >> Agreed, that would make sense. > > I agree, too. > I'll try this in v2 patch that changes the PHY state to PHY_UP and calls > phy_start_machine(), only when the PHY was started before hibernation. > If I understand correctly, it will be like that: > > phydev->link = 0; Even this may go into the if clause. If PHY isn't started then phydev->link should be 0 anyway. > if (phy_is_started(phydev)) { > phydev->state = PHY_UP; > phy_start_machine(phydev); > } > Yes, this is what was meant. Thanks. > Thank you, > > --- > Best Regards, > Kunihiko Hayashi > > >
Hi Heiner, On Fri, 30 Nov 2018 07:20:27 +0100 <hkallweit1@gmail.com> wrote: > On 30.11.2018 05:37, Kunihiko Hayashi wrote: > > Hi Heiner Florian, > > > > Thank you for your comments. > > > > On Thu, 29 Nov 2018 16:37:48 -0800 <f.fainelli@gmail.com> wrote: > > > >> > >> > >> On 11/29/2018 2:47 PM, Heiner Kallweit wrote: > >>> On 29.11.2018 09:12, Kunihiko Hayashi wrote: > >>>> Even though the link is down before entering hibernation, > >>>> there is an issue that the network interface always links up after resuming > >>>> from hibernation. > >>>> > >>>> The phydev->state is PHY_READY before enabling the network interface, so > >>>> the link is down. After resuming from hibernation, the phydev->state is > >>>> forcibly set to PHY_UP in mdio_bus_phy_restore(), and the link becomes up. > >>>> > >>>> This patch expects to solve the issue by changing phydev->state to PHY_UP > >>>> only when the link is up. > >>>> > >>>> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> > >>>> --- > >>>> drivers/net/phy/phy_device.c | 6 ++++-- > >>>> 1 file changed, 4 insertions(+), 2 deletions(-) > >>>> > >>>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > >>>> index ab33d17..d5bba0f 100644 > >>>> --- a/drivers/net/phy/phy_device.c > >>>> +++ b/drivers/net/phy/phy_device.c > >>>> @@ -309,8 +309,10 @@ static int mdio_bus_phy_restore(struct device *dev) > >>>> return ret; > >>>> > >>>> /* The PHY needs to renegotiate. */ > >>>> - phydev->link = 0; > >>>> - phydev->state = PHY_UP; > >>>> + if (phydev->link) { > >>>> + phydev->link = 0; > >>>> + phydev->state = PHY_UP; > >>>> + } > >>>> > >>> Thanks for reporting. I agree that it isn't right to unconditionally set > >>> PHY_UP, because we don't know whether the PHY was started before > >>> hibernation. However I don't think using phydev->link as criteria is > >>> right. Example would be: PHY was started before hibernation, but w/o link. > >>> In this case we want to set PHY_UP to start an aneg, because a cable may > >>> have been plugged in whilst system was sleeping. > > > > Indeed. I didn't consider the case that the PHY was started but a cable was > > unplugged before hibernation. > > > >>> So I think, similar to phy_stop_machine, we should use state >= UP and > >>> state != HALTED as criteria, and also phy_start_machine() would need to > >>> be called only if this criteria is met. > >>> > >>> It may make sense to add a helper for checking whether PHY is in a > >>> started state (>=UP && !=HALTED), because we need this in more than > >>> one place. > >> > >> Agreed, that would make sense. > > > > I agree, too. > > I'll try this in v2 patch that changes the PHY state to PHY_UP and calls > > phy_start_machine(), only when the PHY was started before hibernation. > > If I understand correctly, it will be like that: > > > > phydev->link = 0; > Even this may go into the if clause. If PHY isn't started then > phydev->link should be 0 anyway. Yes. To clarify more, this will go into the if clause. > > > if (phy_is_started(phydev)) { > > phydev->state = PHY_UP; > > phy_start_machine(phydev); > > } > > > Yes, this is what was meant. Thanks. Thank you, --- Best Regards, Kunihiko Hayashi
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index ab33d17..d5bba0f 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -309,8 +309,10 @@ static int mdio_bus_phy_restore(struct device *dev) return ret; /* The PHY needs to renegotiate. */ - phydev->link = 0; - phydev->state = PHY_UP; + if (phydev->link) { + phydev->link = 0; + phydev->state = PHY_UP; + } phy_start_machine(phydev);
Even though the link is down before entering hibernation, there is an issue that the network interface always links up after resuming from hibernation. The phydev->state is PHY_READY before enabling the network interface, so the link is down. After resuming from hibernation, the phydev->state is forcibly set to PHY_UP in mdio_bus_phy_restore(), and the link becomes up. This patch expects to solve the issue by changing phydev->state to PHY_UP only when the link is up. Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> --- drivers/net/phy/phy_device.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) -- 2.7.4