[PATCH] [ARM] twd: Allow twd rescaling to match cpu frequency
Linus Walleij
linus.ml.walleij at gmail.com
Fri Nov 12 07:39:50 EST 2010
Hi Colin,
2010/9/2 Colin Cross <ccross at android.com>:
> The clock to the ARM TWD local timer scales with the cpu
> frequency. To allow the cpu frequency to change while
> maintaining a constant TWD frequency, pick a lower target
> frequency for the TWD and use the prescaler to divide down
> to the closest lower frequency.
>
> This patch provides a new initialization function that takes
> a target TWD frequency and the relation between the cpu
> clock and the TWD clock, required to be an integer divider
>>= 2 by the ARM spec. It also provides a function to be
> called from cpufreq drivers to set the prescaler whenever
> the cpu frequency changes.
What's the status of this patch?
We have basically the same problem so we'd really like
a generic solution to this problem.
Our only comment is that we cannot see the reason for
not using the CPUfreq notifiers as most scaling code
is, but I assume there is some specific reason for this?
Unless something holds this back, could you post it to
Russells patch tracker, we might have an add-on patch
for the U8500 later.
Yours,
Linus Walleij
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