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.stras...@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.
>
