patches.renesas/0351-ARM-shmobile-r8a73a4-safeguard-against-wrong-clk_set.patch

From 7f23ada85cac9bd9892c5571a62dfb2cebe1dc53 Mon Sep 17 00:00:00 2001
From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Date: Fri, 21 Jun 2013 09:10:35 +0200
Subject: ARM: shmobile: r8a73a4: safeguard against wrong clk_set_rate() uses

clk_set_rate() should only be called with exact rates, returned by
clk_round_rate(). However, it is still good to verify, that the value,
passed to clock's .set_rate() method is at least valid. This patch adds
such a check for the Z-clock on r8a73a4.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
(cherry picked from commit d1c3c959f2206dad0582876af2510aded4f9eac5)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
 arch/arm/mach-shmobile/clock-r8a73a4.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-shmobile/clock-r8a73a4.c b/arch/arm/mach-shmobile/clock-r8a73a4.c
index 824789c2..22f10ff4 100644
--- a/arch/arm/mach-shmobile/clock-r8a73a4.c
+++ b/arch/arm/mach-shmobile/clock-r8a73a4.c
@@ -225,16 +225,28 @@ static int zclk_set_rate(struct clk *clk, unsigned long rate)
 		goto done;
 	}
 
-	frqcrc = clk->mapped_reg + (FRQCRC - (u32)clk->enable_reg);
+	/*
+	 * Users are supposed to first call clk_set_rate() only with
+	 * clk_round_rate() results. So, we don't fix wrong rates here, but
+	 * guard against them anyway
+	 */
 
 	p_rate = clk_get_rate(clk->parent);
 	if (rate == p_rate) {
 		val = 0;
 	} else {
 		step = DIV_ROUND_CLOSEST(p_rate, 32);
+
+		if (rate > p_rate || rate < step) {
+			ret = -EINVAL;
+			goto done;
+		}
+
 		val = 32 - rate / step;
 	}
 
+	frqcrc = clk->mapped_reg + (FRQCRC - (u32)clk->enable_reg);
+
 	iowrite32((ioread32(frqcrc) & ~(clk->div_mask << clk->enable_bit)) |
 		  (val << clk->enable_bit), frqcrc);
 
-- 
1.8.4.3.gca3854a