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SubjectRe: [PATCH 01/11] clk: sunxi-ng: Don't set k if width is 0 for nkmp plls
Hi,

On Sat, Dec 30, 2017 at 10:01:53PM +0100, Jernej Skrabec wrote:
> For example, A83T have nmp plls which are modelled as nkmp plls. Since k
> is not specified, it has offset 0, shift 0 and lowest value 1. This
> means that LSB bit is always set to 1, which may change clock rate.
>
> Fix that by applying k factor only if k width is greater than 0.
>
> Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>

This looks fine...

> ---
> drivers/clk/sunxi-ng/ccu_nkmp.c | 21 +++++++++++++--------
> 1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.c b/drivers/clk/sunxi-ng/ccu_nkmp.c
> index e58c95787f94..709f528af2b3 100644
> --- a/drivers/clk/sunxi-ng/ccu_nkmp.c
> +++ b/drivers/clk/sunxi-ng/ccu_nkmp.c
> @@ -81,7 +81,7 @@ static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw,
> unsigned long parent_rate)
> {
> struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
> - unsigned long n, m, k, p;
> + unsigned long n, m, k = 1, p;
> u32 reg;
>
> reg = readl(nkmp->common.base + nkmp->common.reg);
> @@ -92,11 +92,13 @@ static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw,
> if (!n)
> n++;
>
> - k = reg >> nkmp->k.shift;
> - k &= (1 << nkmp->k.width) - 1;
> - k += nkmp->k.offset;
> - if (!k)
> - k++;
> + if (nkmp->k.width) {
> + k = reg >> nkmp->k.shift;
> + k &= (1 << nkmp->k.width) - 1;
> + k += nkmp->k.offset;
> + if (!k)
> + k++;
> + }

... but could you add a comment there to explain why you're using a
different construct than the one used for the other factors?

Thanks!
Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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