Enable arm_global_timer for Zynq brakes boot

Sören Brinkmann soren.brinkmann at xilinx.com
Fri Aug 9 13:48:05 EDT 2013


On Fri, Aug 09, 2013 at 10:27:57AM -0700, Stephen Boyd wrote:
> On 08/09, Daniel Lezcano wrote:
> > 
> > yes, but at least the broadcast mechanism should send an IPI to cpu0 to
> > wake it up, no ? As Stephen stated this kind of configuration should has
> > never been tested before so the tick broadcast code is not handling this
> > case properly IMHO.
> > 
> 
> If you have a per-cpu tick device that isn't suffering from
> FEAT_C3_STOP why wouldn't you use that for the tick versus a
> per-cpu tick device that has FEAT_C3_STOP? It sounds like there
> is a bug in the preference logic or you should boost the rating
> of the arm global timer above the twd. Does this patch help? It
> should make the arm global timer the tick device and whatever the
> cadence timer you have into the broadcast device.

I'm not sure I'm getting this right. But neither the cadence_ttc nor the
arm_global_timer have the FEAT_C3_STOP flag set. So, shouldn't they be
treated equally even with your change?

	Sören





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