From: Andrew Morton <akpm@osdl.org>
Date: Sat, 25 Mar 2006 09:51:51 +0000 (-0800)
Subject: [PATCH] cpufreq: speedstep-smi asm fix
X-Git-Tag: v2.6.17-rc1~735
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f081a529f808ed450c22553de7b3275e0ffde9a0;p=platform%2Fkernel%2Flinux-3.10.git

[PATCH] cpufreq: speedstep-smi asm fix

Fix bug identified by Linus Torvalds <torvalds@osdl.org>: the `out'
instruction depends upon the state of memory_data[], so we need to tell gcc
that before executing it. (The opcode, not gcc).

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=5553

Thanks to Antonio Ospite <ospite@studenti.unina.it> for testing.

Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c b/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c
index 28cc5d5..cfc4276e 100644
--- a/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c
+++ b/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c
@@ -75,7 +75,9 @@ static int speedstep_smi_ownership (void)
 	__asm__ __volatile__(
 		"out %%al, (%%dx)\n"
 		: "=D" (result)
-		: "a" (command), "b" (function), "c" (0), "d" (smi_port), "D" (0), "S" (magic)
+		: "a" (command), "b" (function), "c" (0), "d" (smi_port),
+			"D" (0), "S" (magic)
+		: "memory"
 	);
 
 	dprintk("result is %x\n", result);