Re: [PATCH] [ARM] twd: Allow twd rescaling to match cpu frequency

[Linus Walleij]

Hi Colin,

2010/9/2 Colin Cross <ccross@xxxxxxxxxxx>:

> 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/