[PATCH 3/5] arm64: dts: renesas: r8a7795: Add cpu capacity-dmips-mhz

[Gaku Inami]

Hi Geert-san,

> -----Original Message-----
> From: geert.uytterhoeven at gmail.com [mailto:geert.uytterhoeven at gmail.com] On Behalf Of Geert Uytterhoeven
> Sent: Monday, March 5, 2018 7:24 PM
[snip]
>
> 411 for the A53 cores sounds a bit low to me, though.
> Documentation/devicetree/bindings/arm/cpu-capacity.txt uses 578.
> 
> Perhaps you already took into account the maximum clock frequencies?
> According to the binding document, you should not do that (cfr.
> "final capacities are 1024 for cluster0 and 446 for cluster1" in the
> bindings doc).

Thanks for your review.

I set 411 for CA53 based on dhrystone measurement and current implementation.

The average in 10 times of measurement as follows:

  cpu   max-freq   dhrystone
  ---------------------------------
  A57   1500 MHz  15532585 lps/s
  A53   1200 MHz   6241541 lps/s

With the value of CA57 is scaled at 1024, I end up with 411 for CA53. 
However, since cpufreq is not available on renesas-devel-20180212-v4.16-rc1,
the final capacity is set by directly using capacity-dmips-mhz in dt as below.

  $ cat /sys/devices/system/cpu/cpu*/cpu_capacity
  1024
  1024
  1024
  1024
  411
  411
  411
  411

Considering cpufreq is available later, is it better to set the value(514)
for CA53 scaled by different maximum frequencies?

Regards,
Inami