On Tue, Dec 26, 2017 at 10:45 PM, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> On 26-12-17, 14:23, Rob Herring wrote:
>> > cpu_opp_table: cpu_opp_table {
>> > compatible = "operating-points-v2";
>> > opp-shared;
>> >
>> > opp00 {
>> > opp-hz = /bits/ 64 <208000000>;
>> > clock-latency-ns = <500000>;
>> > power-domain-opp = <&domain_opp_1>;
>>
>> What is this? opp00 here is not a device. One OPP should not point to
>> another. "power-domain-opp" is only supposed to appear in devices
>> alongside power-domains properties.
>
> There are two type of devices:
>
> A.) With fixed performance state requirements and they will have the
> new "required-opp" property in the device node itself as you said.
>
> B.) Devices which can do DVFS (CPU, MMC, LCD, etc) and those may need
> a different performance state of the domain for their individual OPPs
> and so we can't have this property in the device all the time.
>
> Does this make sense ?
No. From the definition for power-domain-opp
"+- power-domain-opp: This contains phandle to one of the OPP nodes of
the master
+ power domain. This specifies the minimum required OPP of the master
domain for
+ the functioning of the device in this OPP (where this property is present).
+ This property can only be set for a device if the device node contains the
+ "power-domains" property. Also, either all or none of the OPP nodes in an OPP
+ table should have it set."
In the above example, you are violating the next to last sentence.
Though, I'm now confused by what the last sentence means.
Rob
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
