Re: [PATCH v7 8/8] PCC: Enable PCC only when needed

[Sudeep Holla <sudeep.holla@arm.com>]

On 22/07/15 02:28, Rafael J. Wysocki wrote:
> On Tuesday, July 21, 2015 04:28:43 PM Sudeep Holla wrote:
>> Hi Rafael,
>>
>> On 21/07/15 15:34, Rafael J. Wysocki wrote:
>>> Hi Sudeep,
>>>
>>> On Tue, Jul 21, 2015 at 11:23 AM, Sudeep Holla <sudeep.holla@arm.com> wrote:
>>>>
>>>>
>>>> On 20/07/15 23:04, Rafael J. Wysocki wrote:

[..]

>>>>>
>>>>>
>>>>> No.  The other client will need to select PCC too.
>>>>
>>>>
>>>> Yes the PCC users/clients selecting PCC is fine and that's already
>>>> done(i.e. ACPI_CPPC_LIB selects PCC). I still don't understand the need
>>>> for this change, also how will other clients possibly select PCC which
>>>> now depends on CPPC_LIB ? e.g. if we have
>>>>
>>>> config ACPI_XYZ_LIB
>>>>           select PCC
>>>>
>>>> config ACPI_XYZ
>>>>           select ACPI_XYZ_LIB
>>>>
>>>> Won't this shout warning: (ACPI_XYZ_LIB && ACPI_CPPC_LIB) selects PCC
>>>> which has unmet direct dependencies (MAILBOX && ACPI && ACPI_CPPC_LIB)
>>>> if ACPI_CPPC_LIB is not selected ?
>>>
>>> That depends on the "depends on" clauses used.  Selecting itself
>>> doesn't cause any dependencies to appear.
>>>
>>
>> Agreed and I am absolutely fine with that. But if you look at this
>> patch, it does
>>
>> config PCC
>> 	bool "Platform Communication Channel Driver"
>> 	depends on ACPI && ACPI_CPPC_LIB
>
> My bad, I've evidently overlooked that.
>
> If PPC is selected from ACPI_CPPC_LIB, the "depends on" above is
> obviously not needed.
>

Thanks for the confirmation.

>> I am fine with ACPI_CPPC_LIB selecting PCC which is already done in
>> earlier patch. I am against making PCC depend on ACPI_CPPC_LIB.
>
> OK, makes sense.  Sorry for the misunderstanding.
>

It's okay, I just wanted to make sure that I am not missing to
understand some kind of dependency.

Regards,
Sudeep