[PATCHv3 0/4] coupled cpuidle state support

Rafael J. Wysocki rjw at sisk.pl
Fri May 18 15:03:55 EDT 2012


On Friday, May 18, 2012, Santosh Shilimkar wrote:
> On Tuesday 08 May 2012 06:27 AM, Colin Cross wrote:
> > On some ARM SMP SoCs (OMAP4460, Tegra 2, and probably more), the
> > cpus cannot be independently powered down, either due to
> > sequencing restrictions (on Tegra 2, cpu 0 must be the last to
> > power down), or due to HW bugs (on OMAP4460, a cpu powering up
> > will corrupt the gic state unless the other cpu runs a work
> > around).  Each cpu has a power state that it can enter without
> > coordinating with the other cpu (usually Wait For Interrupt, or
> > WFI), and one or more "coupled" power states that affect blocks
> > shared between the cpus (L2 cache, interrupt controller, and
> > sometimes the whole SoC).  Entering a coupled power state must
> > be tightly controlled on both cpus.
> > 
> 
> [...]
> 
> > This series has been tested and reviewed by Santosh and Kevin
> > for OMAP4, which has a cpuidle series ready for 3.5, and Tegra
> > and Exynos5 patches are in progress.  I think this is ready to
> > go in.  Lean, are you maintaining a cpuidle tree for linux-next?
> > If not, I can publish a tree for linux-next, or this could go in
> > through Arnd's tree.
> 
> I haven't seen any response so far on who is lining up this
> series for 3.5 ? Not sure if it made it to linux-next either.

That should be Len, but he's been silent recently.

How urgent is it?

Rafael



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