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

[Michael Ellerman]

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?

cheers