Re: [PATCH] clk: rockchip: Fix PLL bandwidth

[Stephen Boyd <sboyd@codeaurora.org>]

On 07/21/2015 01:41 PM, Douglas Anderson wrote:
> In the TRM we see that BWADJ is "a 12-bit bus that selects the values
> 1-4096 for the bandwidth divider (NB)":
>   NB = BWADJ[11:0] + 1
> The recommended setting of NB: NB = NF / 2.
>
> So:
>    NB = NF / 2
>    BWADJ[11:0] + 1 = NF / 2
>    BWADJ[11:0] = NF / 2 - 1
>
> Right now, we have:
>
> {                                               \
>          .rate   = _rate##U,                     \
>          .nr = _nr,                              \
>          .nf = _nf,                              \
>          .no = _no,                              \
>          .bwadj = (_nf >> 1),                    \
> }
>
> That means we set bwadj to NF / 2, not NF / 2 - 1
>
> All of this is a bit confusing because we specify "NR" (the 1-based
> value), "NF" (the 1-based value), "NO" (the 1-based value), but
> "BWADJ" (the 0-based value) instead of "NB" (the 1-based value).
>
> Let's change to working with "NB" and fix the off by one error.  This
> may affect PLL jitter in a small way (hopefully for the better).
>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
>

There's no Fixes tag or stable Cc so I take it this isn't fixing any 
manifesting regression, more of a visual inspection bug find?

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