[PATCH] mdio_bus: suppress err message for reset gpio EPROBE_DEFER

[PATCH] mdio_bus: suppress err message for reset gpio EPROBE_DEFER

[Grygorii Strashko]

The mdio_bus may have dependencies from GPIO controller and so got
deferred. Now it will print error message every time -EPROBE_DEFER is
returned from:
__mdiobus_register()
 |-devm_gpiod_get_optional()
without actually identifying error code.

"mdio_bus 4a101000.mdio: mii_bus 4a101000.mdio couldn't get reset GPIO"

Hence, suppress error message when devm_gpiod_get_optional() returning
-EPROBE_DEFER case.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
 drivers/net/phy/mdio_bus.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 757e950fb745..54fc13043656 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -546,10 +546,11 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 	/* de-assert bus level PHY GPIO reset */
 	gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(gpiod)) {
-		dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
-			bus->id);
+		err = PTR_ERR(gpiod);
+		if (err != -EPROBE_DEFER)
+			dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO %d\n", bus->id, err);
 		device_del(&bus->dev);
-		return PTR_ERR(gpiod);
+		return err;
 	} else	if (gpiod) {
 		bus->reset_gpiod = gpiod;
 
-- 
2.17.1

Re: [PATCH] mdio_bus: suppress err message for reset gpio EPROBE_DEFER

[Heiner Kallweit]

Am 18.11.2020 um 15:24 schrieb Grygorii Strashko:
> The mdio_bus may have dependencies from GPIO controller and so got
> deferred. Now it will print error message every time -EPROBE_DEFER is
> returned from:
> __mdiobus_register()
>  |-devm_gpiod_get_optional()
> without actually identifying error code.
> 
> "mdio_bus 4a101000.mdio: mii_bus 4a101000.mdio couldn't get reset GPIO"
> 
> Hence, suppress error message when devm_gpiod_get_optional() returning
> -EPROBE_DEFER case.
> 
> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
> ---
>  drivers/net/phy/mdio_bus.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
> index 757e950fb745..54fc13043656 100644
> --- a/drivers/net/phy/mdio_bus.c
> +++ b/drivers/net/phy/mdio_bus.c
> @@ -546,10 +546,11 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
>  	/* de-assert bus level PHY GPIO reset */
>  	gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
>  	if (IS_ERR(gpiod)) {
> -		dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
> -			bus->id);
> +		err = PTR_ERR(gpiod);
> +		if (err != -EPROBE_DEFER)
> +			dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO %d\n", bus->id, err);
>  		device_del(&bus->dev);
> -		return PTR_ERR(gpiod);
> +		return err;
>  	} else	if (gpiod) {
>  		bus->reset_gpiod = gpiod;
>  
> 

Using dev_err_probe() here would simplify the code.

Re: [PATCH] mdio_bus: suppress err message for reset gpio EPROBE_DEFER

[Grygorii Strashko]

On 19/11/2020 14:30, Heiner Kallweit wrote:
> Am 18.11.2020 um 15:24 schrieb Grygorii Strashko:
>> The mdio_bus may have dependencies from GPIO controller and so got
>> deferred. Now it will print error message every time -EPROBE_DEFER is
>> returned from:
>> __mdiobus_register()
>>   |-devm_gpiod_get_optional()
>> without actually identifying error code.
>>
>> "mdio_bus 4a101000.mdio: mii_bus 4a101000.mdio couldn't get reset GPIO"
>>
>> Hence, suppress error message when devm_gpiod_get_optional() returning
>> -EPROBE_DEFER case.
>>
>> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
>> ---
>>   drivers/net/phy/mdio_bus.c | 7 ++++---
>>   1 file changed, 4 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
>> index 757e950fb745..54fc13043656 100644
>> --- a/drivers/net/phy/mdio_bus.c
>> +++ b/drivers/net/phy/mdio_bus.c
>> @@ -546,10 +546,11 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
>>   	/* de-assert bus level PHY GPIO reset */
>>   	gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
>>   	if (IS_ERR(gpiod)) {
>> -		dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
>> -			bus->id);
>> +		err = PTR_ERR(gpiod);
>> +		if (err != -EPROBE_DEFER)
>> +			dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO %d\n", bus->id, err);
>>   		device_del(&bus->dev);
>> -		return PTR_ERR(gpiod);
>> +		return err;
>>   	} else	if (gpiod) {
>>   		bus->reset_gpiod = gpiod;
>>   
>>
> 
> Using dev_err_probe() here would simplify the code.
> 

this was my first though, but was not sure if it's correct as dev_err_probe() will use dev
to store defer reason, but the same 'dev' is deleted on the next line.

I also thought about using bus->parent, but it's not always provided.

So, if you think dev_err_probe(0) can be used - I can change and re-send.

-- 
Best regards,
grygorii

Re: [PATCH] mdio_bus: suppress err message for reset gpio EPROBE_DEFER

[Heiner Kallweit]

Am 19.11.2020 um 14:38 schrieb Grygorii Strashko:
> 
> 
> On 19/11/2020 14:30, Heiner Kallweit wrote:
>> Am 18.11.2020 um 15:24 schrieb Grygorii Strashko:
>>> The mdio_bus may have dependencies from GPIO controller and so got
>>> deferred. Now it will print error message every time -EPROBE_DEFER is
>>> returned from:
>>> __mdiobus_register()
>>>   |-devm_gpiod_get_optional()
>>> without actually identifying error code.
>>>
>>> "mdio_bus 4a101000.mdio: mii_bus 4a101000.mdio couldn't get reset GPIO"
>>>
>>> Hence, suppress error message when devm_gpiod_get_optional() returning
>>> -EPROBE_DEFER case.
>>>
>>> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
>>> ---
>>>   drivers/net/phy/mdio_bus.c | 7 ++++---
>>>   1 file changed, 4 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
>>> index 757e950fb745..54fc13043656 100644
>>> --- a/drivers/net/phy/mdio_bus.c
>>> +++ b/drivers/net/phy/mdio_bus.c
>>> @@ -546,10 +546,11 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
>>>       /* de-assert bus level PHY GPIO reset */
>>>       gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
>>>       if (IS_ERR(gpiod)) {
>>> -        dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
>>> -            bus->id);
>>> +        err = PTR_ERR(gpiod);
>>> +        if (err != -EPROBE_DEFER)
>>> +            dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO %d\n", bus->id, err);
>>>           device_del(&bus->dev);
>>> -        return PTR_ERR(gpiod);
>>> +        return err;
>>>       } else    if (gpiod) {
>>>           bus->reset_gpiod = gpiod;
>>>  
>>
>> Using dev_err_probe() here would simplify the code.
>>
> 
> this was my first though, but was not sure if it's correct as dev_err_probe() will use dev
> to store defer reason, but the same 'dev' is deleted on the next line.
> 
If you look at device_del() you see that it calls driver_deferred_probe_del()
which frees the reason string. Means you're right in a way that storing
the deferral reason doesn't provide any benefit here, but it also doesn't
hurt.
Good thing about using dev_err_probe() is also that it prints a debug info
in case of deferral what may help people chasing an issue involving this
deferral.

> I also thought about using bus->parent, but it's not always provided.
> 
> So, if you think dev_err_probe(0) can be used - I can change and re-send.
>