Re: [PATCH] arm: bcm2835: Add the PMU to the devicetree.

[Peter Zijlstra]

On Thu, May 17, 2018 at 06:55:26PM +0200, Stefan Wahren wrote:
> > Vince Weaver <vincent.weaver@xxxxxxxxx> hat am 17. Mai 2018 um 18:34 geschrieben:
> > On Thu, 17 May 2018, Stefan Wahren wrote:
> > > > Eric Anholt <eric@xxxxxxxxxx> hat am 17. Mai 2018 um 15:17 geschrieben:

> > > > The a53 and a7 counters seem to match up, so we advertise a7 so that
> > > > arm32 can probe.
> > 
> > so how closely did you look at the a53/a7 differences?  I see some major 
> > differences, especially with the CPU_CYCLES event (0xff vs 0x11).
> > 
> > The proper fix here might be to add a cortex-a53 PMU entry to the armv7 
> > code rather than trying to treat it as a cortex-a7.
> 
> we like to use the PMU of BCM2837 SoC (4x A53 cores) under arm32 and arm64.
> 
> What is the right way (tm) to the define the DT compatibles?
> Does the arm32 PMU driver need patching for proper A53 support?

I'm completely clueless on all of this; Mark might have ideas.