[RFC PATCH net v3] net: phy: Fix the issue that netif always links up after resuming

[RFC PATCH net v3] net: phy: Fix the issue that netif always links up after resuming

[Kunihiko Hayashi]

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 adds a new convenient function to check whether the PHY is in
a started state, and expects to solve the issue by changing phydev->state
to PHY_UP and calling phy_start_machine() only when the PHY is started.

Suggested-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---

Changes since v2:
 - add mutex lock/unlock for changing phydev->state
 - check whether the mutex is locked in phy_is_started()
 
Changes since v1:
 - introduce a new helper function phy_is_started() and use it instead of
   checking link status
 - replace checking phydev->state with phy_is_started() in
   phy_stop_machine()

drivers/net/phy/phy.c        |  2 +-
 drivers/net/phy/phy_device.c | 12 +++++++++---
 include/linux/phy.h          | 13 +++++++++++++
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 1d73ac3..f484d03 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -670,7 +670,7 @@ void phy_stop_machine(struct phy_device *phydev)
 	cancel_delayed_work_sync(&phydev->state_queue);
 
 	mutex_lock(&phydev->lock);
-	if (phydev->state > PHY_UP && phydev->state != PHY_HALTED)
+	if (phy_is_started(phydev))
 		phydev->state = PHY_UP;
 	mutex_unlock(&phydev->lock);
 }
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index ab33d17..4897d24 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -309,10 +309,16 @@ static int mdio_bus_phy_restore(struct device *dev)
 		return ret;
 
 	/* The PHY needs to renegotiate. */
-	phydev->link = 0;
-	phydev->state = PHY_UP;
+	mutex_lock(&phydev->lock);
+	if (phy_is_started(phydev)) {
+		phydev->state = PHY_UP;
+		mutex_unlock(&phydev->lock);
+		phydev->link = 0;
+		phy_start_machine(phydev);
+	} else {
+		mutex_unlock(&phydev->lock);
+	}
 
-	phy_start_machine(phydev);
 
 	return 0;
 }
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 3ea87f7..dd21537 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -898,6 +898,19 @@ static inline bool phy_is_pseudo_fixed_link(struct phy_device *phydev)
 }
 
 /**
+ * phy_is_started - Convenience function for testing whether a PHY is in
+ * a started state
+ * @phydev: the phy_device struct
+ *
+ * The caller must have taken the phy_device mutex lock.
+ */
+static inline bool phy_is_started(struct phy_device *phydev)
+{
+	WARN_ON(!mutex_is_locked(&phydev->lock));
+	return phydev->state >= PHY_UP && phydev->state != PHY_HALTED;
+}
+
+/**
  * phy_write_mmd - Convenience function for writing a register
  * on an MMD on a given PHY.
  * @phydev: The phy_device struct
-- 
2.7.4

Re: [RFC PATCH net v3] net: phy: Fix the issue that netif always links up after resuming

[Kunihiko Hayashi]

Hi,

Gentle ping...
Are there any comments about changes since v2?

v2: https://www.spinics.net/lists/netdev/msg536926.html

Thank you,

On Mon, 3 Dec 2018 17:22:29 +0900 <hayashi.kunihiko@socionext.com> 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 adds a new convenient function to check whether the PHY is in
> a started state, and expects to solve the issue by changing phydev->state
> to PHY_UP and calling phy_start_machine() only when the PHY is started.
> 
> Suggested-by: Heiner Kallweit <hkallweit1@gmail.com>
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> ---
> 
> Changes since v2:
>  - add mutex lock/unlock for changing phydev->state
>  - check whether the mutex is locked in phy_is_started()
>  
> Changes since v1:
>  - introduce a new helper function phy_is_started() and use it instead of
>    checking link status
>  - replace checking phydev->state with phy_is_started() in
>    phy_stop_machine()
> 
> drivers/net/phy/phy.c        |  2 +-
>  drivers/net/phy/phy_device.c | 12 +++++++++---
>  include/linux/phy.h          | 13 +++++++++++++
>  3 files changed, 23 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> index 1d73ac3..f484d03 100644
> --- a/drivers/net/phy/phy.c
> +++ b/drivers/net/phy/phy.c
> @@ -670,7 +670,7 @@ void phy_stop_machine(struct phy_device *phydev)
>  	cancel_delayed_work_sync(&phydev->state_queue);
>  
>  	mutex_lock(&phydev->lock);
> -	if (phydev->state > PHY_UP && phydev->state != PHY_HALTED)
> +	if (phy_is_started(phydev))
>  		phydev->state = PHY_UP;
>  	mutex_unlock(&phydev->lock);
>  }
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index ab33d17..4897d24 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -309,10 +309,16 @@ static int mdio_bus_phy_restore(struct device *dev)
>  		return ret;
>  
>  	/* The PHY needs to renegotiate. */
> -	phydev->link = 0;
> -	phydev->state = PHY_UP;
> +	mutex_lock(&phydev->lock);
> +	if (phy_is_started(phydev)) {
> +		phydev->state = PHY_UP;
> +		mutex_unlock(&phydev->lock);
> +		phydev->link = 0;
> +		phy_start_machine(phydev);
> +	} else {
> +		mutex_unlock(&phydev->lock);
> +	}
>  
> -	phy_start_machine(phydev);
>  
>  	return 0;
>  }
> diff --git a/include/linux/phy.h b/include/linux/phy.h
> index 3ea87f7..dd21537 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -898,6 +898,19 @@ static inline bool phy_is_pseudo_fixed_link(struct phy_device *phydev)
>  }
>  
>  /**
> + * phy_is_started - Convenience function for testing whether a PHY is in
> + * a started state
> + * @phydev: the phy_device struct
> + *
> + * The caller must have taken the phy_device mutex lock.
> + */
> +static inline bool phy_is_started(struct phy_device *phydev)
> +{
> +	WARN_ON(!mutex_is_locked(&phydev->lock));
> +	return phydev->state >= PHY_UP && phydev->state != PHY_HALTED;
> +}
> +
> +/**
>   * phy_write_mmd - Convenience function for writing a register
>   * on an MMD on a given PHY.
>   * @phydev: The phy_device struct
> -- 
> 2.7.4

---
Best Regards,
Kunihiko Hayashi

Re: [RFC PATCH net v3] net: phy: Fix the issue that netif always links up after resuming

[Heiner Kallweit]

On 17.12.2018 07:41, Kunihiko Hayashi wrote:
> Hi,
> 
> Gentle ping...
> Are there any comments about changes since v2?
> 
> v2: https://www.spinics.net/lists/netdev/msg536926.html
> 
> Thank you,
> 
> On Mon, 3 Dec 2018 17:22:29 +0900 <hayashi.kunihiko@socionext.com> 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 adds a new convenient function to check whether the PHY is in
>> a started state, and expects to solve the issue by changing phydev->state
>> to PHY_UP and calling phy_start_machine() only when the PHY is started.
>>
This convenience function and the related change to phy_stop() are part of
the following already and don't need to be part of your patch.
https://patchwork.ozlabs.org/patch/1014171/

>> Suggested-by: Heiner Kallweit <hkallweit1@gmail.com>
>> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
>> ---
>>
>> Changes since v2:
>>  - add mutex lock/unlock for changing phydev->state
>>  - check whether the mutex is locked in phy_is_started()
>>  
>> Changes since v1:
>>  - introduce a new helper function phy_is_started() and use it instead of
>>    checking link status
>>  - replace checking phydev->state with phy_is_started() in
>>    phy_stop_machine()
>>
>> drivers/net/phy/phy.c        |  2 +-
>>  drivers/net/phy/phy_device.c | 12 +++++++++---
>>  include/linux/phy.h          | 13 +++++++++++++
>>  3 files changed, 23 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
>> index 1d73ac3..f484d03 100644
>> --- a/drivers/net/phy/phy.c
>> +++ b/drivers/net/phy/phy.c
>> @@ -670,7 +670,7 @@ void phy_stop_machine(struct phy_device *phydev)
>>  	cancel_delayed_work_sync(&phydev->state_queue);
>>  
>>  	mutex_lock(&phydev->lock);
>> -	if (phydev->state > PHY_UP && phydev->state != PHY_HALTED)
>> +	if (phy_is_started(phydev))
>>  		phydev->state = PHY_UP;

I'm wondering whether we need to do this. If the PHY is attached,
then mdio_bus_phy_suspend() calls phy_stop_machine() which does
exactly the same. If the PHY is not attached, then we don't have
to do anything. Therefore I think we just have to do the same as
in mdio_bus_phy_resume():

if (phydev->attached_dev && phydev->adjust_link)
	phy_start_machine(phydev);

Can you test this?

>>  	mutex_unlock(&phydev->lock);
>>  }
>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
>> index ab33d17..4897d24 100644
>> --- a/drivers/net/phy/phy_device.c
>> +++ b/drivers/net/phy/phy_device.c
>> @@ -309,10 +309,16 @@ static int mdio_bus_phy_restore(struct device *dev)
>>  		return ret;
>>  
>>  	/* The PHY needs to renegotiate. */
>> -	phydev->link = 0;
>> -	phydev->state = PHY_UP;
>> +	mutex_lock(&phydev->lock);
>> +	if (phy_is_started(phydev)) {
>> +		phydev->state = PHY_UP;
>> +		mutex_unlock(&phydev->lock);
>> +		phydev->link = 0;
>> +		phy_start_machine(phydev);
>> +	} else {
>> +		mutex_unlock(&phydev->lock);
>> +	}
>>  
>> -	phy_start_machine(phydev);
>>  
>>  	return 0;
>>  }
>> diff --git a/include/linux/phy.h b/include/linux/phy.h
>> index 3ea87f7..dd21537 100644
>> --- a/include/linux/phy.h
>> +++ b/include/linux/phy.h
>> @@ -898,6 +898,19 @@ static inline bool phy_is_pseudo_fixed_link(struct phy_device *phydev)
>>  }
>>  
>>  /**
>> + * phy_is_started - Convenience function for testing whether a PHY is in
>> + * a started state
>> + * @phydev: the phy_device struct
>> + *
>> + * The caller must have taken the phy_device mutex lock.
>> + */
>> +static inline bool phy_is_started(struct phy_device *phydev)
>> +{
>> +	WARN_ON(!mutex_is_locked(&phydev->lock));
>> +	return phydev->state >= PHY_UP && phydev->state != PHY_HALTED;
>> +}
>> +
>> +/**
>>   * phy_write_mmd - Convenience function for writing a register
>>   * on an MMD on a given PHY.
>>   * @phydev: The phy_device struct
>> -- 
>> 2.7.4
> 
> ---
> Best Regards,
> Kunihiko Hayashi
> 
> 
> 

Re: [RFC PATCH net v3] net: phy: Fix the issue that netif always links up after resuming

[Heiner Kallweit]

On 17.12.2018 19:41, Heiner Kallweit wrote:
> On 17.12.2018 07:41, Kunihiko Hayashi wrote:
>> Hi,
>>
>> Gentle ping...
>> Are there any comments about changes since v2?
>>
>> v2: https://www.spinics.net/lists/netdev/msg536926.html
>>
>> Thank you,
>>
>> On Mon, 3 Dec 2018 17:22:29 +0900 <hayashi.kunihiko@socionext.com> 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 adds a new convenient function to check whether the PHY is in
>>> a started state, and expects to solve the issue by changing phydev->state
>>> to PHY_UP and calling phy_start_machine() only when the PHY is started.
>>>
> This convenience function and the related change to phy_stop() are part of
> the following already and don't need to be part of your patch.
> https://patchwork.ozlabs.org/patch/1014171/
> 
>>> Suggested-by: Heiner Kallweit <hkallweit1@gmail.com>
>>> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
>>> ---
>>>
>>> Changes since v2:
>>>  - add mutex lock/unlock for changing phydev->state
>>>  - check whether the mutex is locked in phy_is_started()
>>>  
>>> Changes since v1:
>>>  - introduce a new helper function phy_is_started() and use it instead of
>>>    checking link status
>>>  - replace checking phydev->state with phy_is_started() in
>>>    phy_stop_machine()
>>>
>>> drivers/net/phy/phy.c        |  2 +-
>>>  drivers/net/phy/phy_device.c | 12 +++++++++---
>>>  include/linux/phy.h          | 13 +++++++++++++
>>>  3 files changed, 23 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
>>> index 1d73ac3..f484d03 100644
>>> --- a/drivers/net/phy/phy.c
>>> +++ b/drivers/net/phy/phy.c
>>> @@ -670,7 +670,7 @@ void phy_stop_machine(struct phy_device *phydev)
>>>  	cancel_delayed_work_sync(&phydev->state_queue);
>>>  
>>>  	mutex_lock(&phydev->lock);
>>> -	if (phydev->state > PHY_UP && phydev->state != PHY_HALTED)
>>> +	if (phy_is_started(phydev))
>>>  		phydev->state = PHY_UP;
> 
> I'm wondering whether we need to do this. If the PHY is attached,
> then mdio_bus_phy_suspend() calls phy_stop_machine() which does
> exactly the same. If the PHY is not attached, then we don't have
> to do anything. Therefore I think we just have to do the same as
> in mdio_bus_phy_resume():
> 
> if (phydev->attached_dev && phydev->adjust_link)
> 	phy_start_machine(phydev);
> 
> Can you test this?
> 
Sorry for the confusion, this comment is related to the next part
of your patch.

>>>  	mutex_unlock(&phydev->lock);
>>>  }
>>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
>>> index ab33d17..4897d24 100644
>>> --- a/drivers/net/phy/phy_device.c
>>> +++ b/drivers/net/phy/phy_device.c
>>> @@ -309,10 +309,16 @@ static int mdio_bus_phy_restore(struct device *dev)
>>>  		return ret;
>>>  
>>>  	/* The PHY needs to renegotiate. */
>>> -	phydev->link = 0;
>>> -	phydev->state = PHY_UP;
>>> +	mutex_lock(&phydev->lock);
>>> +	if (phy_is_started(phydev)) {
>>> +		phydev->state = PHY_UP;
>>> +		mutex_unlock(&phydev->lock);
>>> +		phydev->link = 0;
>>> +		phy_start_machine(phydev);
>>> +	} else {
>>> +		mutex_unlock(&phydev->lock);
>>> +	}
>>>  
>>> -	phy_start_machine(phydev);
>>>  
>>>  	return 0;
>>>  }
>>> diff --git a/include/linux/phy.h b/include/linux/phy.h
>>> index 3ea87f7..dd21537 100644
>>> --- a/include/linux/phy.h
>>> +++ b/include/linux/phy.h
>>> @@ -898,6 +898,19 @@ static inline bool phy_is_pseudo_fixed_link(struct phy_device *phydev)
>>>  }
>>>  
>>>  /**
>>> + * phy_is_started - Convenience function for testing whether a PHY is in
>>> + * a started state
>>> + * @phydev: the phy_device struct
>>> + *
>>> + * The caller must have taken the phy_device mutex lock.
>>> + */
>>> +static inline bool phy_is_started(struct phy_device *phydev)
>>> +{
>>> +	WARN_ON(!mutex_is_locked(&phydev->lock));
>>> +	return phydev->state >= PHY_UP && phydev->state != PHY_HALTED;
>>> +}
>>> +
>>> +/**
>>>   * phy_write_mmd - Convenience function for writing a register
>>>   * on an MMD on a given PHY.
>>>   * @phydev: The phy_device struct
>>> -- 
>>> 2.7.4
>>
>> ---
>> Best Regards,
>> Kunihiko Hayashi
>>
>>
>>
> 

Re: [RFC PATCH net v3] net: phy: Fix the issue that netif always links up after resuming

[Kunihiko Hayashi]

Hi Heiner,

On Mon, 17 Dec 2018 19:43:31 +0100 <hkallweit1@gmail.com> wrote:

> On 17.12.2018 19:41, Heiner Kallweit wrote:
> > On 17.12.2018 07:41, Kunihiko Hayashi wrote:
> >> Hi,
> >>
> >> Gentle ping...
> >> Are there any comments about changes since v2?
> >>
> >> v2: https://www.spinics.net/lists/netdev/msg536926.html
> >>
> >> Thank you,
> >>
> >> On Mon, 3 Dec 2018 17:22:29 +0900 <hayashi.kunihiko@socionext.com> 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 adds a new convenient function to check whether the PHY is in
> >>> a started state, and expects to solve the issue by changing phydev->state
> >>> to PHY_UP and calling phy_start_machine() only when the PHY is started.
> >>>
> > This convenience function and the related change to phy_stop() are part of
> > the following already and don't need to be part of your patch.
> > https://patchwork.ozlabs.org/patch/1014171/

I see. I'll follow your patch when necessary.

> >>> Suggested-by: Heiner Kallweit <hkallweit1@gmail.com>
> >>> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> >>> ---
> >>>
> >>> Changes since v2:
> >>>  - add mutex lock/unlock for changing phydev->state
> >>>  - check whether the mutex is locked in phy_is_started()
> >>>  
> >>> Changes since v1:
> >>>  - introduce a new helper function phy_is_started() and use it instead of
> >>>    checking link status
> >>>  - replace checking phydev->state with phy_is_started() in
> >>>    phy_stop_machine()
> >>>
> >>> drivers/net/phy/phy.c        |  2 +-
> >>>  drivers/net/phy/phy_device.c | 12 +++++++++---
> >>>  include/linux/phy.h          | 13 +++++++++++++
> >>>  3 files changed, 23 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> >>> index 1d73ac3..f484d03 100644
> >>> --- a/drivers/net/phy/phy.c
> >>> +++ b/drivers/net/phy/phy.c
> >>> @@ -670,7 +670,7 @@ void phy_stop_machine(struct phy_device *phydev)
> >>>  	cancel_delayed_work_sync(&phydev->state_queue);
> >>>  
> >>>  	mutex_lock(&phydev->lock);
> >>> -	if (phydev->state > PHY_UP && phydev->state != PHY_HALTED)
> >>> +	if (phy_is_started(phydev))
> >>>  		phydev->state = PHY_UP;
> > 
> > I'm wondering whether we need to do this. If the PHY is attached,
> > then mdio_bus_phy_suspend() calls phy_stop_machine() which does
> > exactly the same. If the PHY is not attached, then we don't have
> > to do anything. Therefore I think we just have to do the same as
> > in mdio_bus_phy_resume():
> > 
> > if (phydev->attached_dev && phydev->adjust_link)
> > 	phy_start_machine(phydev);

Agreed.

Although the original code changed phydev->state,
it seems that it's only enough to
- call phy_stop_machine() in mdio_bus_phy_suspend()
- call phy_start_machine() in mdio_bus_phy_resume() and mdio_bus_phy_restore()
if the PHY is attached.

> > Can you test this?

I tested your code instead of applying my entire patch, and I confirmed
that the code solved the issue in my environment.

Do you make new patch instead of my patch?
(and I can add Reported-by: for the issue and Tested-by:)

Thank you,


> > 
> Sorry for the confusion, this comment is related to the next part
> of your patch.
> 
> >>>  	mutex_unlock(&phydev->lock);
> >>>  }
> >>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> >>> index ab33d17..4897d24 100644
> >>> --- a/drivers/net/phy/phy_device.c
> >>> +++ b/drivers/net/phy/phy_device.c
> >>> @@ -309,10 +309,16 @@ static int mdio_bus_phy_restore(struct device *dev)
> >>>  		return ret;
> >>>  
> >>>  	/* The PHY needs to renegotiate. */
> >>> -	phydev->link = 0;
> >>> -	phydev->state = PHY_UP;
> >>> +	mutex_lock(&phydev->lock);
> >>> +	if (phy_is_started(phydev)) {
> >>> +		phydev->state = PHY_UP;
> >>> +		mutex_unlock(&phydev->lock);
> >>> +		phydev->link = 0;
> >>> +		phy_start_machine(phydev);
> >>> +	} else {
> >>> +		mutex_unlock(&phydev->lock);
> >>> +	}
> >>>  
> >>> -	phy_start_machine(phydev);
> >>>  
> >>>  	return 0;
> >>>  }
> >>> diff --git a/include/linux/phy.h b/include/linux/phy.h
> >>> index 3ea87f7..dd21537 100644
> >>> --- a/include/linux/phy.h
> >>> +++ b/include/linux/phy.h
> >>> @@ -898,6 +898,19 @@ static inline bool phy_is_pseudo_fixed_link(struct phy_device *phydev)
> >>>  }
> >>>  
> >>>  /**
> >>> + * phy_is_started - Convenience function for testing whether a PHY is in
> >>> + * a started state
> >>> + * @phydev: the phy_device struct
> >>> + *
> >>> + * The caller must have taken the phy_device mutex lock.
> >>> + */
> >>> +static inline bool phy_is_started(struct phy_device *phydev)
> >>> +{
> >>> +	WARN_ON(!mutex_is_locked(&phydev->lock));
> >>> +	return phydev->state >= PHY_UP && phydev->state != PHY_HALTED;
> >>> +}
> >>> +
> >>> +/**
> >>>   * phy_write_mmd - Convenience function for writing a register
> >>>   * on an MMD on a given PHY.
> >>>   * @phydev: The phy_device struct
> >>> -- 
> >>> 2.7.4
> >>
> >> ---
> >> Best Regards,
> >> Kunihiko Hayashi
> >>
> >>
> >>
> > 

---
Best Regards,
Kunihiko Hayashi

Re: [RFC PATCH net v3] net: phy: Fix the issue that netif always links up after resuming

[Heiner Kallweit]

On 18.12.2018 07:25, Kunihiko Hayashi wrote:
> Hi Heiner,
> 
> On Mon, 17 Dec 2018 19:43:31 +0100 <hkallweit1@gmail.com> wrote:
> 
>> On 17.12.2018 19:41, Heiner Kallweit wrote:
>>> On 17.12.2018 07:41, Kunihiko Hayashi wrote:
>>>> Hi,
>>>>
>>>> Gentle ping...
>>>> Are there any comments about changes since v2?
>>>>
>>>> v2: https://www.spinics.net/lists/netdev/msg536926.html
>>>>
>>>> Thank you,
>>>>
>>>> On Mon, 3 Dec 2018 17:22:29 +0900 <hayashi.kunihiko@socionext.com> 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 adds a new convenient function to check whether the PHY is in
>>>>> a started state, and expects to solve the issue by changing phydev->state
>>>>> to PHY_UP and calling phy_start_machine() only when the PHY is started.
>>>>>
>>> This convenience function and the related change to phy_stop() are part of
>>> the following already and don't need to be part of your patch.
>>> https://patchwork.ozlabs.org/patch/1014171/
> 
> I see. I'll follow your patch when necessary.
> 
>>>>> Suggested-by: Heiner Kallweit <hkallweit1@gmail.com>
>>>>> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
>>>>> ---
>>>>>
>>>>> Changes since v2:
>>>>>  - add mutex lock/unlock for changing phydev->state
>>>>>  - check whether the mutex is locked in phy_is_started()
>>>>>  
>>>>> Changes since v1:
>>>>>  - introduce a new helper function phy_is_started() and use it instead of
>>>>>    checking link status
>>>>>  - replace checking phydev->state with phy_is_started() in
>>>>>    phy_stop_machine()
>>>>>
>>>>> drivers/net/phy/phy.c        |  2 +-
>>>>>  drivers/net/phy/phy_device.c | 12 +++++++++---
>>>>>  include/linux/phy.h          | 13 +++++++++++++
>>>>>  3 files changed, 23 insertions(+), 4 deletions(-)
>>>>>
>>>>> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
>>>>> index 1d73ac3..f484d03 100644
>>>>> --- a/drivers/net/phy/phy.c
>>>>> +++ b/drivers/net/phy/phy.c
>>>>> @@ -670,7 +670,7 @@ void phy_stop_machine(struct phy_device *phydev)
>>>>>  	cancel_delayed_work_sync(&phydev->state_queue);
>>>>>  
>>>>>  	mutex_lock(&phydev->lock);
>>>>> -	if (phydev->state > PHY_UP && phydev->state != PHY_HALTED)
>>>>> +	if (phy_is_started(phydev))
>>>>>  		phydev->state = PHY_UP;
>>>
>>> I'm wondering whether we need to do this. If the PHY is attached,
>>> then mdio_bus_phy_suspend() calls phy_stop_machine() which does
>>> exactly the same. If the PHY is not attached, then we don't have
>>> to do anything. Therefore I think we just have to do the same as
>>> in mdio_bus_phy_resume():
>>>
>>> if (phydev->attached_dev && phydev->adjust_link)
>>> 	phy_start_machine(phydev);
> 
> Agreed.
> 
> Although the original code changed phydev->state,
> it seems that it's only enough to
> - call phy_stop_machine() in mdio_bus_phy_suspend()
> - call phy_start_machine() in mdio_bus_phy_resume() and mdio_bus_phy_restore()
> if the PHY is attached.
> 
>>> Can you test this?
> 
> I tested your code instead of applying my entire patch, and I confirmed
> that the code solved the issue in my environment.
> 
> Do you make new patch instead of my patch?
> (and I can add Reported-by: for the issue and Tested-by:)
> 
Up to you. It's fine with me if you submit the patch, but I can also do it
and mention you in Reported-by and Tested-by. Just let me know.

> Thank you,
> 
> 
>>>
>> Sorry for the confusion, this comment is related to the next part
>> of your patch.
>>
>>>>>  	mutex_unlock(&phydev->lock);
>>>>>  }
>>>>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
>>>>> index ab33d17..4897d24 100644
>>>>> --- a/drivers/net/phy/phy_device.c
>>>>> +++ b/drivers/net/phy/phy_device.c
>>>>> @@ -309,10 +309,16 @@ static int mdio_bus_phy_restore(struct device *dev)
>>>>>  		return ret;
>>>>>  
>>>>>  	/* The PHY needs to renegotiate. */
>>>>> -	phydev->link = 0;
>>>>> -	phydev->state = PHY_UP;
>>>>> +	mutex_lock(&phydev->lock);
>>>>> +	if (phy_is_started(phydev)) {
>>>>> +		phydev->state = PHY_UP;
>>>>> +		mutex_unlock(&phydev->lock);
>>>>> +		phydev->link = 0;
>>>>> +		phy_start_machine(phydev);
>>>>> +	} else {
>>>>> +		mutex_unlock(&phydev->lock);
>>>>> +	}
>>>>>  
>>>>> -	phy_start_machine(phydev);
>>>>>  
>>>>>  	return 0;
>>>>>  }
>>>>> diff --git a/include/linux/phy.h b/include/linux/phy.h
>>>>> index 3ea87f7..dd21537 100644
>>>>> --- a/include/linux/phy.h
>>>>> +++ b/include/linux/phy.h
>>>>> @@ -898,6 +898,19 @@ static inline bool phy_is_pseudo_fixed_link(struct phy_device *phydev)
>>>>>  }
>>>>>  
>>>>>  /**
>>>>> + * phy_is_started - Convenience function for testing whether a PHY is in
>>>>> + * a started state
>>>>> + * @phydev: the phy_device struct
>>>>> + *
>>>>> + * The caller must have taken the phy_device mutex lock.
>>>>> + */
>>>>> +static inline bool phy_is_started(struct phy_device *phydev)
>>>>> +{
>>>>> +	WARN_ON(!mutex_is_locked(&phydev->lock));
>>>>> +	return phydev->state >= PHY_UP && phydev->state != PHY_HALTED;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>>   * phy_write_mmd - Convenience function for writing a register
>>>>>   * on an MMD on a given PHY.
>>>>>   * @phydev: The phy_device struct
>>>>> -- 
>>>>> 2.7.4
>>>>
>>>> ---
>>>> Best Regards,
>>>> Kunihiko Hayashi
>>>>
>>>>
>>>>
>>>
> 
> ---
> Best Regards,
> Kunihiko Hayashi
> 
> 
> 

Re: [RFC PATCH net v3] net: phy: Fix the issue that netif always links up after resuming

[Kunihiko Hayashi]

Hi Heiner,

On Tue, 18 Dec 2018 07:44:33 +0100 <hkallweit1@gmail.com> wrote:

> On 18.12.2018 07:25, Kunihiko Hayashi wrote:
> > Hi Heiner,
> > 
> > On Mon, 17 Dec 2018 19:43:31 +0100 <hkallweit1@gmail.com> wrote:
> > 
> >> On 17.12.2018 19:41, Heiner Kallweit wrote:
> >>> On 17.12.2018 07:41, Kunihiko Hayashi wrote:
> >>>> Hi,
> >>>>
> >>>> Gentle ping...
> >>>> Are there any comments about changes since v2?
> >>>>
> >>>> v2: https://www.spinics.net/lists/netdev/msg536926.html
> >>>>
> >>>> Thank you,
> >>>>
> >>>> On Mon, 3 Dec 2018 17:22:29 +0900 <hayashi.kunihiko@socionext.com> 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 adds a new convenient function to check whether the PHY is in
> >>>>> a started state, and expects to solve the issue by changing phydev->state
> >>>>> to PHY_UP and calling phy_start_machine() only when the PHY is started.
> >>>>>
> >>> This convenience function and the related change to phy_stop() are part of
> >>> the following already and don't need to be part of your patch.
> >>> https://patchwork.ozlabs.org/patch/1014171/
> > 
> > I see. I'll follow your patch when necessary.
> > 
> >>>>> Suggested-by: Heiner Kallweit <hkallweit1@gmail.com>
> >>>>> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> >>>>> ---
> >>>>>
> >>>>> Changes since v2:
> >>>>>  - add mutex lock/unlock for changing phydev->state
> >>>>>  - check whether the mutex is locked in phy_is_started()
> >>>>>  
> >>>>> Changes since v1:
> >>>>>  - introduce a new helper function phy_is_started() and use it instead of
> >>>>>    checking link status
> >>>>>  - replace checking phydev->state with phy_is_started() in
> >>>>>    phy_stop_machine()
> >>>>>
> >>>>> drivers/net/phy/phy.c        |  2 +-
> >>>>>  drivers/net/phy/phy_device.c | 12 +++++++++---
> >>>>>  include/linux/phy.h          | 13 +++++++++++++
> >>>>>  3 files changed, 23 insertions(+), 4 deletions(-)
> >>>>>
> >>>>> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> >>>>> index 1d73ac3..f484d03 100644
> >>>>> --- a/drivers/net/phy/phy.c
> >>>>> +++ b/drivers/net/phy/phy.c
> >>>>> @@ -670,7 +670,7 @@ void phy_stop_machine(struct phy_device *phydev)
> >>>>>  	cancel_delayed_work_sync(&phydev->state_queue);
> >>>>>  
> >>>>>  	mutex_lock(&phydev->lock);
> >>>>> -	if (phydev->state > PHY_UP && phydev->state != PHY_HALTED)
> >>>>> +	if (phy_is_started(phydev))
> >>>>>  		phydev->state = PHY_UP;
> >>>
> >>> I'm wondering whether we need to do this. If the PHY is attached,
> >>> then mdio_bus_phy_suspend() calls phy_stop_machine() which does
> >>> exactly the same. If the PHY is not attached, then we don't have
> >>> to do anything. Therefore I think we just have to do the same as
> >>> in mdio_bus_phy_resume():
> >>>
> >>> if (phydev->attached_dev && phydev->adjust_link)
> >>> 	phy_start_machine(phydev);
> > 
> > Agreed.
> > 
> > Although the original code changed phydev->state,
> > it seems that it's only enough to
> > - call phy_stop_machine() in mdio_bus_phy_suspend()
> > - call phy_start_machine() in mdio_bus_phy_resume() and mdio_bus_phy_restore()
> > if the PHY is attached.
> > 
> >>> Can you test this?
> > 
> > I tested your code instead of applying my entire patch, and I confirmed
> > that the code solved the issue in my environment.
> > 
> > Do you make new patch instead of my patch?
> > (and I can add Reported-by: for the issue and Tested-by:)
> > 
> Up to you. It's fine with me if you submit the patch, but I can also do it
> and mention you in Reported-by and Tested-by. Just let me know.

I see. I'll make and submit the patch as a fix for the issue.

Thank you,

> 
> > Thank you,
> > 
> > 
> >>>
> >> Sorry for the confusion, this comment is related to the next part
> >> of your patch.
> >>
> >>>>>  	mutex_unlock(&phydev->lock);
> >>>>>  }
> >>>>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> >>>>> index ab33d17..4897d24 100644
> >>>>> --- a/drivers/net/phy/phy_device.c
> >>>>> +++ b/drivers/net/phy/phy_device.c
> >>>>> @@ -309,10 +309,16 @@ static int mdio_bus_phy_restore(struct device *dev)
> >>>>>  		return ret;
> >>>>>  
> >>>>>  	/* The PHY needs to renegotiate. */
> >>>>> -	phydev->link = 0;
> >>>>> -	phydev->state = PHY_UP;
> >>>>> +	mutex_lock(&phydev->lock);
> >>>>> +	if (phy_is_started(phydev)) {
> >>>>> +		phydev->state = PHY_UP;
> >>>>> +		mutex_unlock(&phydev->lock);
> >>>>> +		phydev->link = 0;
> >>>>> +		phy_start_machine(phydev);
> >>>>> +	} else {
> >>>>> +		mutex_unlock(&phydev->lock);
> >>>>> +	}
> >>>>>  
> >>>>> -	phy_start_machine(phydev);
> >>>>>  
> >>>>>  	return 0;
> >>>>>  }
> >>>>> diff --git a/include/linux/phy.h b/include/linux/phy.h
> >>>>> index 3ea87f7..dd21537 100644
> >>>>> --- a/include/linux/phy.h
> >>>>> +++ b/include/linux/phy.h
> >>>>> @@ -898,6 +898,19 @@ static inline bool phy_is_pseudo_fixed_link(struct phy_device *phydev)
> >>>>>  }
> >>>>>  
> >>>>>  /**
> >>>>> + * phy_is_started - Convenience function for testing whether a PHY is in
> >>>>> + * a started state
> >>>>> + * @phydev: the phy_device struct
> >>>>> + *
> >>>>> + * The caller must have taken the phy_device mutex lock.
> >>>>> + */
> >>>>> +static inline bool phy_is_started(struct phy_device *phydev)
> >>>>> +{
> >>>>> +	WARN_ON(!mutex_is_locked(&phydev->lock));
> >>>>> +	return phydev->state >= PHY_UP && phydev->state != PHY_HALTED;
> >>>>> +}
> >>>>> +
> >>>>> +/**
> >>>>>   * phy_write_mmd - Convenience function for writing a register
> >>>>>   * on an MMD on a given PHY.
> >>>>>   * @phydev: The phy_device struct
> >>>>> -- 
> >>>>> 2.7.4
> >>>>
> >>>> ---
> >>>> Best Regards,
> >>>> Kunihiko Hayashi
> >>>>
> >>>>
> >>>>
> >>>
> > 
> > ---
> > Best Regards,
> > Kunihiko Hayashi
> > 
> > 
> > 

---
Best Regards,
Kunihiko Hayashi