diff mbox series

[5.10,688/717] clk: ingenic: Fix divider calculation with div tables

Message ID 20201228125053.932528023@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

gregkh@linuxfoundation.org Dec. 28, 2020, 12:51 p.m. UTC 
From: Paul Cercueil <paul@crapouillou.net>

commit 11a163f2c7d6a9f27ce144cd7e367a81c851621a upstream.

The previous code assumed that a higher hardware value always resulted
in a bigger divider, which is correct for the regular clocks, but is
an invalid assumption when a divider table is provided for the clock.

Perfect example of this is the PLL0_HALF clock, which applies a /2
divider with the hardware value 0, and a /1 divider otherwise.

Fixes: a9fa2893fcc6 ("clk: ingenic: Add support for divider tables")
Cc: <stable@vger.kernel.org> # 5.2
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20201212135733.38050-1-paul@crapouillou.net
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/clk/ingenic/cgu.c |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)
diff mbox series

Patch

--- a/drivers/clk/ingenic/cgu.c
+++ b/drivers/clk/ingenic/cgu.c
@@ -392,15 +392,21 @@  static unsigned int
 ingenic_clk_calc_hw_div(const struct ingenic_cgu_clk_info *clk_info,
 			unsigned int div)
 {
-	unsigned int i;
+	unsigned int i, best_i = 0, best = (unsigned int)-1;
 
 	for (i = 0; i < (1 << clk_info->div.bits)
 				&& clk_info->div.div_table[i]; i++) {
-		if (clk_info->div.div_table[i] >= div)
-			return i;
+		if (clk_info->div.div_table[i] >= div &&
+		    clk_info->div.div_table[i] < best) {
+			best = clk_info->div.div_table[i];
+			best_i = i;
+
+			if (div == best)
+				break;
+		}
 	}
 
-	return i - 1;
+	return best_i;
 }
 
 static unsigned