4.16-stable review patch. If anyone has any objections, please let me know.
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From: Andrzej Hajda a.hajda@samsung.com
[ Upstream commit a8321e7887410a2b2e80ab89d1ef7b30562658ea ]
Rates declared in PLL rate tables should match exactly rates calculated from PLL coefficients. If that is not the case, rate of the PLL's child clock might be set not as expected. For instance, if in the PLL rates table we have a 393216000 Hz entry and the real value as returned by the PLL's recalc_rate callback is 393216003, after setting PLL's clk rate to 393216000 clk_get_rate will return 393216003. If we now attempt to set rate of a PLL's child divider clock to 393216000/2 its rate will be 131072001, rather than 196608000. That is, the divider will be set to 3 instead of 2, because 393216003/2 is greater than 196608000.
To fix this issue declared rates are changed to exactly match rates generated by the PLL, as calculated from the P, M, S, K coefficients.
In this patch an erroneous P value for 74176002 output frequency is also corrected.
Signed-off-by: Andrzej Hajda a.hajda@samsung.com Acked-by: Chanwoo Choi cw00.choi@samsung.com Acked-by: Tomasz Figa tomasz.figa@gmail.com Signed-off-by: Sylwester Nawrocki s.nawrocki@samsung.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/clk/samsung/clk-exynos3250.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/clk/samsung/clk-exynos3250.c +++ b/drivers/clk/samsung/clk-exynos3250.c @@ -698,7 +698,7 @@ static const struct samsung_pll_rate_tab PLL_36XX_RATE(144000000, 96, 2, 3, 0), PLL_36XX_RATE( 96000000, 128, 2, 4, 0), PLL_36XX_RATE( 84000000, 112, 2, 4, 0), - PLL_36XX_RATE( 80000004, 106, 2, 4, 43691), + PLL_36XX_RATE( 80000003, 106, 2, 4, 43691), PLL_36XX_RATE( 73728000, 98, 2, 4, 19923), PLL_36XX_RATE( 67737598, 270, 3, 5, 62285), PLL_36XX_RATE( 65535999, 174, 2, 5, 49982), @@ -734,7 +734,7 @@ static const struct samsung_pll_rate_tab PLL_36XX_RATE(148352005, 98, 2, 3, 59070), PLL_36XX_RATE(108000000, 144, 2, 4, 0), PLL_36XX_RATE( 74250000, 99, 2, 4, 0), - PLL_36XX_RATE( 74176002, 98, 3, 4, 59070), + PLL_36XX_RATE( 74176002, 98, 2, 4, 59070), PLL_36XX_RATE( 54054000, 216, 3, 5, 14156), PLL_36XX_RATE( 54000000, 144, 2, 5, 0), { /* sentinel */ }