Enable arm_global_timer for Zynq brakes boot

Sören Brinkmann soren.brinkmann at xilinx.com
Mon Aug 12 12:24:57 EDT 2013


On Mon, Aug 12, 2013 at 09:20:19AM -0700, Stephen Boyd wrote:
> On 08/12/13 09:03, Sören Brinkmann wrote:
> > 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 finally got to test your patch. Unfortunately, it makes the system
> > hang even earlier:
> 
> Sorry it had a bug depending on the registration order. Can you try this
> one (tabs are probably spaces, sorry)? I will go read through this
> thread to see if we already covered the registration order.

What is the base for your patch? I based my GT enable patch on 3.11-rc3
and for consistency in our debugging, I didn't move it elsewhere since.
Your patch doesn't apply cleanly on it. I see if I can work it out, just
let me know if it depends on something not available in 3.11-rc3.

	Sören





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