Re: [PATCH v4 2/2] clk: bcm2835: Minimise clock jitter for PCM clock

From: Stephen Boyd
Date: Fri Jun 02 2017 - 18:45:39 EST


On 06/01, Phil Elwell wrote:
> Fractional clock dividers generate accurate average frequencies but
> with jitter, particularly when the integer divisor is small.
>
> Introduce a new metric of clock accuracy to penalise clocks with a good
> average but worse jitter compared to clocks with an average which is no
> better but with lower jitter. The metric is the ideal rate minus the
> worse deviation from that ideal using the nearest integer divisors.
>
> Use this metric for parent selection for clocks requiring low jitter
> (currently just PCM).
>
> Signed-off-by: Phil Elwell <phil@xxxxxxxxxxxxxxx>
> Reviewed-by: Eric Anholt <eric@xxxxxxxxxx>
> Acked-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
> ---

Applied to clk-next

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