linux-kernel - [PATCH 2/4] msm: scm: Fix improper register assignment

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Message-Id: <1298573085-23217-3-git-send-email-sboyd@codeaurora.org>
Date:	Thu, 24 Feb 2011 10:44:43 -0800
From:	Stephen Boyd <sboyd@...eaurora.org>
To:	David Brown <davidb@...eaurora.org>
Cc:	linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org
Subject: [PATCH 2/4] msm: scm: Fix improper register assignment

Assign the registers used in the inline assembly immediately
before the inline assembly block. This ensures the compiler
doesn't optimize away dead register assignments when it
shouldn't.

Signed-off-by: Stephen Boyd <sboyd@...eaurora.org>
---
 arch/arm/mach-msm/scm.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-msm/scm.c b/arch/arm/mach-msm/scm.c
index ba57b5a..5eddf54 100644
--- a/arch/arm/mach-msm/scm.c
+++ b/arch/arm/mach-msm/scm.c
@@ -264,13 +264,16 @@ u32 scm_get_version(void)
 {
 	int context_id;
 	static u32 version = -1;
-	register u32 r0 asm("r0") = 0x1 << 8;
-	register u32 r1 asm("r1") = (u32)&context_id;
+	register u32 r0 asm("r0");
+	register u32 r1 asm("r1");
 
 	if (version != -1)
 		return version;
 
 	mutex_lock(&scm_lock);
+
+	r0 = 0x1 << 8;
+	r1 = (u32)&context_id;
 	asm volatile(
 		__asmeq("%0", "r1")
 		__asmeq("%1", "r0")
-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

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