Re: [PATCH] clk: samsung: exynos5420: The EPLL rate table corrections

From: Sylwester Nawrocki
Date: Mon Jul 31 2017 - 08:26:50 EST


On 07/21/2017 01:19 PM, Sylwester Nawrocki wrote:
This patch fixes values of the EPLL K coefficient and changes
the EPLL output frequency values to match exactly what is
possible to achieve with given M, P, S, K coefficients.
This allows to avoid rounding errors and unexpected frequency
being set with clk_set_rate(), due to recalc_rate returning
different values than the PLL rate specified in the
exynos5420_epll_24mhz_tbl table. E.g. this prevents a case
where two consecutive clk_set_rate() calls with same argument
result in different PLL output frequency.

The PLL output frequencies have been calculated with formula:

f = fxtal * (M * 2^16 + K) / (P * 2^S) / 2^16

where fxtal = 24000000.

Fixes: 9842452acd ("clk: samsung: exynos542x: Add EPLL rate table")
Signed-off-by: Sylwester Nawrocki<s.nawrocki@xxxxxxxxxxx>

Stephen, Mike,

Could you apply this patch directly for v4.12-rcX?
It fixes code added in v4.12.

--
Thanks,
Sylwester