On 08/23/2013 02:54 AM, Scott Wood wrote:

On Thu, 2013-08-22 at 11:20 +0530, Deepthi Dharwar wrote:

quoted

On 08/22/2013 01:38 AM, Scott Wood wrote:

quoted

On Wed, 2013-08-21 at 10:23 +0530, Deepthi Dharwar wrote:

quoted

On 08/19/2013 11:47 PM, Scott Wood wrote:

quoted

What actual functionality is common to all powerpc but not common to
other arches?

The functionality here is idle states on powerpc  like the snooze loop
that is common.
Also, the basic registration of the driver, hotplug notifier etc for
powerpc.

The snooze loop uses things like SPRN_PURR, get_lppaca(), and CTRL which
aren't common to all PPC (they might be common to all book3s64).  I also
don't see any hook for the low power mode entry -- is "snooze" just a
busy loop plus the de-emphasis stuff like HMT and CTRL[RUN]?  I'm not
familiar with the term "snooze" in this context.  I don't think we'd use
anything like that on our chips; we'd always at least "wait" or "doze"
depending on the chip.

Duly noted. Lot of stuff are common across book3s64. So my later
versions of this patchset does just that. (V5 posted out yesterday).
The driver is common only to IBM-POWER platform. Other PPC variants
can have their own driver.

It's not clear what is powerpc-specific about the notifier -- perhaps it
should go in drivers/cpuidle/.

Currently all the arcs have their own hotplug notifier. Unifying this
across all archs is a challenge that needs to be taken going forward.

Thanks for the review.
Regards,
Deepthi

quoted

quoted

The way forward is to give this file a more appropriate name based on
the hardware that it actually targets -- and to refactor it so that the
answer to that question is not complicated.

Sure, thanks.
Our idea was to have POWER archs idle states merged at the first go.
Only that is what is enabled in the current version (V4 posted out)
( Code is enabled for PSERIES and POWERNV only)
If needed, other POWERPC archs might benefit by extending the same
driver, that is why it is named cpuidle-powerpc.c

But if having cpuidle backend-driver separately for other powerpc arcs
makes sense such that each one have their own state information etc
then it makes sense to name the files as cpuidle-power.c,
cpuilde-ppc32.c and so on.

Thanks.

-Scott



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