openwrt/target/linux/brcm2708/patches-4.9/0194-clk-bcm2835-Correct-the-prediv-logic.patch

From a9913dccdeaabca37343d0d8b0a48cda1e434e02 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Wed, 1 Mar 2017 16:06:53 +0000
Subject: [PATCH] clk-bcm2835: Correct the prediv logic

If a clock has the prediv flag set, both the integer and fractional
parts must be scaled when calculating the resulting frequency.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
---
 drivers/clk/bcm/clk-bcm2835.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -616,8 +616,10 @@ static unsigned long bcm2835_pll_get_rat
 	using_prediv = cprman_read(cprman, data->ana_reg_base + 4) &
 		data->ana->fb_prediv_mask;
 
-	if (using_prediv)
+	if (using_prediv) {
 		ndiv *= 2;
+		fdiv *= 2;
+	}
 
 	return bcm2835_pll_rate_from_divisors(parent_rate, ndiv, fdiv, pdiv);
 }