[oe] hawkboard at 456 Mhz?

[Frans Meulenbroeks]

Hi,

In the openembedded repository I saw the following patch:
http://cgit.openembedded.org/cgit.cgi/openembedded/tree/recipes/linux/linux-davinci/da850_omapl138_opp456mhz.patch
This seems to suggest that it is possible to run the hawkboard at 456
Mhz (and yeah: I know it is out of spec and out of warranty, but for
an experiment it would be quite helpful for me).
I've build the kernel with openembedded, the patch is applied,
CONF_CPU_FREQ is defined, but the control hook in /sys is not there.
I've also tried tweaking the file with the settings (ds850.c) but to no avail.

Anyone a suggestion on how to get this done?

Thanks alot! FM

PS: a way to downclock would also be fine for my experiment. For a
disk benchmark I would like to know what part of the time it takes to
read data actually is caused by the device and which comes from the
os.
Assumption is that the device time is independent of the CPU clock and
that the os time is roughly linear with the cpu frequency. (and yes, I
use an access pattern that tries to avoid pre-caching by the device).