Index: head/sys/arm/allwinner/clkng/aw_clk_nm.c
===================================================================
--- head/sys/arm/allwinner/clkng/aw_clk_nm.c
+++ head/sys/arm/allwinner/clkng/aw_clk_nm.c
@@ -153,7 +153,8 @@
 	for (m = min_m; m <= max_m; ) {
 		for (n = min_n; n <= max_n; ) {
 			cur = fparent / n / m;
-			if (abs(*fout - cur) < abs(*fout - best)) {
+			if (clk_freq_diff(*fout, cur) <
+			    clk_freq_diff(*fout, best)) {
 				best = cur;
 				*factor_n = n;
 				*factor_m = m;
@@ -196,7 +197,8 @@
 			clknode_get_freq(p_clk, &fparent);
 
 			cur = aw_clk_nm_find_best(sc, fparent, fout, &n, &m);
-			if (abs((*fout - cur)) < abs((*fout - best))) {
+			if (clk_freq_diff(*fout, cur) <
+			    clk_freq_diff(*fout, best)) {
 				best = cur;
 				best_parent = p_idx;
 				best_n = n;
Index: head/sys/dev/extres/clk/clk.h
===================================================================
--- head/sys/dev/extres/clk/clk.h
+++ head/sys/dev/extres/clk/clk.h
@@ -135,6 +135,12 @@
 int clk_set_parent_by_clk(clk_t clk, clk_t parent);
 const char *clk_get_name(clk_t clk);
 
+static inline uint64_t
+clk_freq_diff(uint64_t x, uint64_t y)
+{
+	return (x >= y ? x - y : y - x);
+}
+
 #ifdef FDT
 int clk_set_assigned(device_t dev, phandle_t node);
 int clk_get_by_ofw_index(device_t dev, phandle_t node, int idx, clk_t *clk);