ACK: [trusty] [PATCH 0/3] cpufreq: powernv

[Tim Gardner]

On 04/30/2014 09:06 AM, Mauricio Faria de Oliveira wrote:
> Hi Tim,
> 
>>> Note that this also changes behavior for powerpc64-smp. I assume that
>>> has been tested ?
>>>
>>> We also need the attached config patch for packaging.
>>
>> Thanks for mentioning that.  I completely missed the config patch.
>>
>> I'll give this another spin and ping back.
> 
> First of all, apologies for the extra delayed response.
> And thanks for applying the patches w/ the required changes.
> 
> 
> Initially I thought of enabling it only for ppc64el, excluding
> common -- any other powerpc flavours.
> But, given I missed the config patch, this doesn't look like any
> position/schedule dates to ask for things. :)
> 
> Nonetheless, the code should exit gracefully where non-supported
> (i.e., powerpc64-smp on POWER5/Mac hardware), for this check in the
> top of init code [1]:
> 
> +       power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
> +       if (!power_mgt) {
> +               pr_warn("power-mgt node not found\n");
> +               return -ENODEV;
> +       }
> 
> .. since that file (actually the 'ibm,opal' dir at all) is not part of
> the device-tree for a POWER5 system (and I can't think of it in Macs),
> which is where the powerpc flavours are supposed to run, IIRC [2].
> 
>     # grep -m1 ^cpu /proc/cpuinfo
>     cpu        : POWER5 (gr)
> 
>     # stat /proc/device-tree/ibm,opal/power-mgt
>     stat: cannot stat `/proc/device-tree/ibm,opal/power-mgt': No such
>     file or directory
> 
> Thanks!
> 
> [1] drivers/cpufreq/powernv-cpufreq.c
>   static int __init powernv_cpufreq_init(void) -> init_powernv_pstates
> [2] http://cdimage.ubuntu.com/releases/14.04/release/
> 

That was my take on it at the time, i.e., non Opal platforms should fail
gracefully.

rtg
-- 
Tim Gardner tim.gardner at canonical.com