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[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>
Andrew Morton há 19 anos atrás
pai
commit
f081a529f8
1 ficheiros alterados com 3 adições e 1 exclusões
  1. 3 1
      arch/i386/kernel/cpu/cpufreq/speedstep-smi.c

+ 3 - 1
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);