On Sun, Sep 22, 2013 at 3:29 PM, David Miller <davem@xxxxxxxxxxxxx> wrote:
> From: Rob Herring <robherring2@xxxxxxxxx>
> Date: Sun, 22 Sep 2013 15:13:35 -0500
>
>> On 09/20/2013 11:44 AM, Sudeep KarkadaNagesha wrote:
>>> On 19/09/13 18:38, David Miller wrote:
>>>> From: Rob Herring <robherring2@xxxxxxxxx>
>>>> Date: Thu, 19 Sep 2013 08:26:04 -0500
>>>>
>>>>> The simple solution here is to just remove the warning. It doesn't
>>>>> appear to me that sparc ever sets the cpu device of_node pointer.
>>>>
>>>> Why wouldn't I want sparc to have this functionality now that the
>>>> code is generically available.
>>>>
>>> Makes sense, but as you mentioned before we need to match other property
>>> names namely "upa-portid", "portid" or "cpuid" for cpu physical id right
>>> ? Are all these 32-bit values ?
>>>
>>>>> Are there any cases on where sparc does have a /cpus node? If so we'd
>>>>> need to make of_get_cpu_node a weak function or depend on a kconfig option.
>>>>
>>>> I already gave a solution to this problem, make the loop iterator be:
>>>>
>>>> for_each_node_by_type(dp, "cpu")
>>>>
>>>
>>> Does it make sense use this only when /cpus is not found ?
>>> IMHO as the number of node in DT increases(which is the case on ARM
>>> platforms) parsing entire tree may be expensive(which can be avoided in
>>> case /cpus is found)
>>
>> Can't you simply do something like this for the search:
>>
>> cpus = of_find_node_by_path("/cpus");
>> if (!cpus && IS_ENABLED(CONFIG_SPARC))
>> cpus = of_find_node_by_path("/");
>> if (!cpus) {
>> pr_warn("Missing cpus node, bailing out\n");
>> return NULL;
>> }
>>
>> for_each_child_of_node(cpus, cpun) {
>
> This doesn't work either Rob. Some UltraSPARC-IV systems put the cpu
> nodes under directories representing the cores.
Okay. Good to know.
> For the third time, the only thing which will work unilaterally is
> the type base iterator I proposed above.
Now that I understand all the variations, I agree.
> Why is there so much resistence to something which has an extremely
> high likelyhood of working everywhere and not requiring any ifdef
> crapola?
Simplifying Sudeep's code a bit while maintaining some level of
validation of the DT layout was my only goal. I guess that validation
really needs to be at build time rather than boot time and there is
some work going on in that area.
Rob
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