machdep.frequency.current handling incomplete ?

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

Hello,
I already noticed that setting machdep.frequency.current to 1000 on the
beaglebone would cause it to hang, even with an external 5V supply.
Setting it to 900 used to work (modulo other problems, which are also
present if I don't change the frequency).

Now that I have X11 running, I tried glxgears. Up to 800Mhz everything
is fine, but with glxgears running, switching the frequency to 900Mhz
causes the same hang. Note that I see this with both my beaglebone and
beaglebone black, so I don't think I have broken hardware.

So I wonder if anyone is aware of something missing to properly switch
the CPU to higher frequencies on the beaglebone ?
Maybe some voltage adjustement in the SoC, or at the tps65217 level ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--