From: Simon Glass <sjg@chromium.org>
Date: Wed, 31 May 2017 23:57:22 +0000 (-0600)
Subject: tegra: clock: Avoid a divide-by-zero error
X-Git-Tag: v2017.07-rc2~54^2~17
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=1c6c7b6bd8961373a506cf7908e9fe61f6042341;p=oweals%2Fu-boot.git

tegra: clock: Avoid a divide-by-zero error

The clock fix-up for tegra is still present in the code. It causes a
divide-by-zero bug after relocation when chain-loading U-Boot from
coreboot. Fix this by adding a check.

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: 7468676 (ARM: tegra: fix clock_get_periph_rate() for UART clocks)
---

diff --git a/arch/arm/mach-tegra/clock.c b/arch/arm/mach-tegra/clock.c
index 76436d8d91..bac42119cd 100644
--- a/arch/arm/mach-tegra/clock.c
+++ b/arch/arm/mach-tegra/clock.c
@@ -339,8 +339,11 @@ unsigned long clock_get_periph_rate(enum periph_id periph_id,
 		 * return value doesn't help. In summary this clock driver is
 		 * quite broken but I'm afraid I have no idea how to fix it
 		 * without completely replacing it.
+		 *
+		 * Be careful to avoid a divide by zero error.
 		 */
-		div -= 2;
+		if (div >= 1)
+			div -= 2;
 		break;
 #endif
 	default: