[PATCH v3] powernv/sensor: Handle OPAL_WRONG_STATE error return

[Vipin K Parashar]

On Monday 06 March 2017 03:03 PM, Michael Ellerman wrote:
> Vipin K Parashar <vipin at linux.vnet.ibm.com> writes:
>
>> OPAL returns OPAL_WRONG_STATE upon failing to provide
>> sensor data due to core sleeping/offline. Added check
>> for OPAL_WRONG_STATE rerurn code with sensor read failure.
>> Also added a log message indicating sensor data being
>> queried for sleeping/offline core.
>>
>> Signed-off-by: Vipin K Parashar <vipin at linux.vnet.ibm.com>
>> ---
>> Changes in v3:
>>   - Added a new case for OPAL_WRONG_STATE in sensor read
>>     along with a log message indicating sleeping/offline core
>>     causing read fail.
>>
>>   arch/powerpc/platforms/powernv/opal-sensor.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/arch/powerpc/platforms/powernv/opal-sensor.c b/arch/powerpc/platforms/powernv/opal-sensor.c
>> index 308efd1..fb6d6bb 100644
>> --- a/arch/powerpc/platforms/powernv/opal-sensor.c
>> +++ b/arch/powerpc/platforms/powernv/opal-sensor.c
>> @@ -64,6 +64,12 @@ int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data)
>>   		*sensor_data = be32_to_cpu(data);
>>   		break;
>>   
>> +	case OPAL_WRONG_STATE:
>> +		pr_notice("%s: Sensor data read failure due to "
>> +				"core sleeping/offline\n", __func__);
> I don't think it should print.
>
> It's not the users fault, or anything they can prevent. It's a
> mis-feature (aka. bug) in the driver that it queries sensors for offline
> CPUs. At least it should be ratelimited.
>
> I thought the entire motivation for the patch in the first place was
> that we were spamming the console with messages?

Yes. Correct.
To avoid flooding console, logged message using pr_notice.
I think, it was suggested in previous reviews to log a message before
returning -EIO.
Shall i directly return -EIO without any log message ?

> cheers
>