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@xxxxxxx> wrote:
On 20/07/15 23:04, Rafael J. Wysocki wrote:
On Monday, July 20, 2015 03:22:37 PM Sudeep Holla wrote:
On 09/07/15 19:04, Ashwin Chaugule wrote:
CPPC is the first client to make use of the PCC Mailbox channel. So
enable it only when CPPC is also enabled.
This sounds like a reverse dependency to me. So if there's some client
unrelated to CPPC using PCC, CPPC_LIB needs to be selected to enable PCC
?
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
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.
Lets assume it's fine to do that. Now if another feature XYZ as in my
example say on x86 selects PCC then you will *get warnings* as we will
not able to select PCC without selecting ACPI_CPPC_LIB after this patch
and x86 will never select ACPI_CPPC_LIB. I did test something like my
XYZ example and it did trigger the warning as I suspected.
I am sorry either I am missing to understand again or unable to express
the problem here :(
OK, for now we enable ACPI_CPPC_LIB on ARM64 and not on x86. When x86
has a PCC client how will that select PCC without ACPI_CPPC_LIB. Sorry
if I am missing to understand something.
Presumably, the new feature will have a Kconfig option associated with
it and it will do "select PCC" too.
As I say I am fine with that and no arguments there.
Regards,
Sudeep
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