From: Will Deacon <will.deacon@arm.com>
Date: Wed, 20 Jul 2011 10:57:03 +0000 (+0100)
Subject: ARM: realview: ensure visibility of writes during reset
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5cb843ca0f781b62dc9793b26926d0b8efef5576;p=linux-beck.git

ARM: realview: ensure visibility of writes during reset

The various reset routines in mach-realview rely on an FPGA to
power-cycle the board after writing some magic runes to memory-mapped
registers.

This patch adds a dsb() following the writes, so that they become
visible before we mdelay(1000) in the arch_reset code. Without this
patch, the timeout would expire sporadically, causing the reset to fail.

Signed-off-by: Will Deacon <will.deacon@arm.com>
---

diff --git a/arch/arm/mach-realview/include/mach/system.h b/arch/arm/mach-realview/include/mach/system.h
index a30f2e3ec178..6657ff231161 100644
--- a/arch/arm/mach-realview/include/mach/system.h
+++ b/arch/arm/mach-realview/include/mach/system.h
@@ -44,6 +44,7 @@ static inline void arch_reset(char mode, const char *cmd)
 	 */
 	if (realview_reset)
 		realview_reset(mode);
+	dsb();
 }
 
 #endif