[PATCH 4.14 103/159] clk: sunxi-ng: nm: Check if requested rate is supported by fractional clock

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chen-Yu Tsai <wens@xxxxxxxx>


[ Upstream commit 4cdbc40d64d4b8303a97e29a52862e4d99502beb ]

The round_rate callback for N-M-factor style clocks does not check if
the requested clock rate is supported by the fractional clock mode.
While this doesn't affect usage in practice, since the clock rates
are also supported through N-M factors, it does not match the set_rate
code.

Add a check to the round_rate callback so it matches the set_rate
callback.

Fixes: 6174a1e24b0d ("clk: sunxi-ng: Add N-M-factor clock support")
Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/clk/sunxi-ng/ccu_nm.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/clk/sunxi-ng/ccu_nm.c
+++ b/drivers/clk/sunxi-ng/ccu_nm.c
@@ -99,6 +99,9 @@ static long ccu_nm_round_rate(struct clk
 	struct ccu_nm *nm = hw_to_ccu_nm(hw);
 	struct _ccu_nm _nm;
 
+	if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate))
+		return rate;
+
 	_nm.min_n = nm->n.min ?: 1;
 	_nm.max_n = nm->n.max ?: 1 << nm->n.width;
 	_nm.min_m = 1;