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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/6] ARM: realview: ensure visibility of writes during reset
Date: Mon,  8 Aug 2011 18:10:20 +0100	[thread overview]
Message-ID: <1312823424-9654-3-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1312823424-9654-1-git-send-email-will.deacon@arm.com>

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>
---
 arch/arm/mach-realview/include/mach/system.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-realview/include/mach/system.h b/arch/arm/mach-realview/include/mach/system.h
index a30f2e3..6657ff2 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
-- 
1.7.0.4

  parent reply	other threads:[~2011-08-08 17:10 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-08 17:10 [PATCH 0/6] Miscellaneous patches for 3.1 and 3.2 Will Deacon
2011-08-08 17:10 ` [PATCH 1/6] ARM: vexpress: determine active tile site before reading tile ID Will Deacon
2011-08-08 17:10 ` Will Deacon [this message]
2011-08-08 21:16   ` [PATCH 2/6] ARM: realview: ensure visibility of writes during reset Rob Herring
2011-08-09  8:32     ` Will Deacon
2011-08-08 17:10 ` [PATCH 3/6] ARM: twd: register clockevents device before enabling PPI Will Deacon
2011-08-08 18:19   ` Marc Zyngier
2011-08-08 17:10 ` [PATCH 4/6] ARM: smp: set thread_info->cpu to hardware CPU number for boot thread Will Deacon
2011-08-08 17:33   ` Stephen Boyd
2011-08-08 18:14     ` Will Deacon
2011-08-08 20:02       ` Russell King - ARM Linux
2011-08-08 20:25         ` Will Deacon
2011-08-09 11:48   ` Sergei Shtylyov
2011-08-09 12:13     ` Will Deacon
2011-08-08 17:10 ` [PATCH 5/6] ARM: cache: detect VIPT aliasing I-cache on ARMv6 Will Deacon
2011-08-08 17:10 ` [PATCH 6/6] ARM: cache: detect PIPT I-cache using CTR Will Deacon

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