Re: [PATCH 1/2] hwmon: (ibmpowernv) Quieten when probing finds no device

[Guenter Roeck <linux@roeck-us.net>]

On 11/01/2014 10:48 AM, Neelesh Gupta wrote:
>
> On 10/31/2014 11:42 PM, Guenter Roeck wrote:
>> On Fri, Oct 31, 2014 at 05:45:22PM +1100, Michael Ellerman wrote:
>>> Because we build kernels with drivers built in for many platforms, it's
>>> normal for the ibmpowernv driver to be loaded on systems that don't have
>>> the appropriate hardware.
>>>
>>> Currently the driver spams the log with:
>>>
>>>    ibmpowernv ibmpowernv.0: Opal node 'sensors' not found
>>>    ibmpowernv: Platfrom driver probe failed
>>>
>>> But there is no error, this machine is not a powernv and doesn't have
>>> the hardware. So change the sensors message to dev_dbg(), and only print
>>> an error about the probe failing if it's not ENODEV.
>>>
>>> Also fix the spelling of "Platfrom" and print the actual error value.
>>>
>>> Signed-off-by: Michael Ellerman<mpe@ellerman.id.au>
>> Neelesh,
>>
>> is there a compatible property in the powernv devicetree which can be
>> used to identify the system ?
>
> I think the driver should not be loaded at first place on *non* powernv platforms.
> Still, we can improve by introducing 'platform_driver.id_table' and moving the
> platform device creation code in platform init 'opal-sensor.c' using
> of_platform_device_create() and just do driver register in module init.
>

Ok with me.

Can you write a patch doing that ?

Thanks,
Guenter

> - Neelesh
>
>>
>> I am ok with applying this patch for the time being, but it would be better
>> if we can change the driver to only instantiate when actually needed.
>>
>> Thanks,
>> Guenter
>>
>>> ---
>>>   drivers/hwmon/ibmpowernv.c | 6 ++++--
>>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/hwmon/ibmpowernv.c b/drivers/hwmon/ibmpowernv.c
>>> index d2bf2c97ae70..6a30eeea94be 100644
>>> --- a/drivers/hwmon/ibmpowernv.c
>>> +++ b/drivers/hwmon/ibmpowernv.c
>>> @@ -181,7 +181,7 @@ static int __init populate_attr_groups(struct platform_device *pdev)
>>>
>>>   	opal = of_find_node_by_path("/ibm,opal/sensors");
>>>   	if (!opal) {
>>> -		dev_err(&pdev->dev, "Opal node 'sensors' not found\n");
>>> +		dev_dbg(&pdev->dev, "Opal node 'sensors' not found\n");
>>>   		return -ENODEV;
>>>   	}
>>>
>>> @@ -335,7 +335,9 @@ static int __init ibmpowernv_init(void)
>>>
>>>   	err = platform_driver_probe(&ibmpowernv_driver, ibmpowernv_probe);
>>>   	if (err) {
>>> -		pr_err("Platfrom driver probe failed\n");
>>> +		if (err != -ENODEV)
>>> +			pr_err("Platform driver probe failed (%d)\n", err);
>>> +
>>>   		goto exit_device_del;
>>>   	}
>>>
>>> --
>>> 1.9.1
>>>
>