Bug#536183: Can't change CPU scaling governor after .29 to .30 upgrade.

["Trent W. Buck" <trentbuck@gmail.com>]

Bastian Blank wrote:
> On Fri, Feb 26, 2010 at 09:57:37AM +1100, Trent W. Buck wrote:
>>     # printf ondemand >/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
>
> It should give an error here.
>
>>     # dmesg | tail -1
>>     [38198.312686] ondemand governor failed, too long transition latency of HW, fallback to performance governor
>
> But now it is clear that the behaviour otherwise is correct. If the
> hardware is not capable to do something, it is no software bug.

The hardware didn't change; the kernel did.  Either the kernel was
wrong to permit on-demand frequency scaling before, or it's wrong to
refuse it now.