[Linux-m32r:00049] [PATCH 2.6.16-rc3] m32r: __cmpxchg_u32 fix

[Hirokazu Takata]

This patch fixes a bug of include/asm-m32r/system.h:__cmpxchg_u32().

  static __inline__ unsigned long
  __cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new);

In __cmpxchg_u32(), the "old" value must not be changed to the previous "*p"
value.  But the former code modifies the previous "*p" value.

A deadlock at _atomic_dec_and_lock sometimes happened due to this bug.

Please apply this patch.

Thanks,

Signed-off-by: Hayato Fujiwara <fujiwara at linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata at linux-m32r.org>
---

 include/asm-m32r/system.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6.16-rc3/include/asm-m32r/system.h
===================================================================
--- linux-2.6.16-rc3.orig/include/asm-m32r/system.h	2006-02-17 22:02:08.701003359 +0900
+++ linux-2.6.16-rc3/include/asm-m32r/system.h	2006-02-17 22:04:13.304341309 +0900
@@ -239,7 +239,7 @@ __cmpxchg_u32(volatile unsigned int *p, 
 		"	bra	2f;		\n"
                 "       .fillinsn		\n"
 		"1:"
-			M32R_UNLOCK" %2, @%1;	\n"
+			M32R_UNLOCK" %0, @%1;	\n"
                 "       .fillinsn		\n"
 		"2:"
 			: "=&r" (retval)

--
Hirokazu Takata <takata at linux-m32r.org>
Linux/M32R Project:  http://www.linux-m32r.org/