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Subject[PATCH] [7/98] i8k: Tell gcc that *regs gets clobbered
2.6.35-longterm review patch.  If anyone has any objections, please let me know.

From: Jim Bos <>

[ upstream commit 6b4e81db2552bad04100e7d5ddeed7e848f53b48 ]

More recent GCC caused the i8k driver to stop working, on Slackware
compiler was upgraded from gcc-4.4.4 to gcc-4.5.1 after which it didn't
work anymore, meaning the driver didn't load or gave total nonsensical

As it turned out the asm(..) statement forgot to mention it modifies the
*regs variable.

Credits to Andi Kleen and Andreas Schwab for providing the fix.

Signed-off-by: Jim Bos <>
Cc: Andi Kleen <>
Cc: Andreas Schwab <>
Signed-off-by: Linus Torvalds <>
Signed-off-by: Andi Kleen <>

Index: linux-2.6.35.y/drivers/char/i8k.c
--- linux-2.6.35.y.orig/drivers/char/i8k.c
+++ linux-2.6.35.y/drivers/char/i8k.c
@@ -141,7 +141,7 @@ static int i8k_smm(struct smm_regs *regs
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n"
- :"=a"(rc)
+ :"=a"(rc), "+m" (*regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
@@ -166,7 +166,8 @@ static int i8k_smm(struct smm_regs *regs
"movl %%edx,0(%%eax)\n\t"
"shrl $8,%%eax\n\t"
- "andl $1,%%eax\n":"=a"(rc)
+ "andl $1,%%eax\n"
+ :"=a"(rc), "+m" (*regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");

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