From: Ralf Baechle Date: Thu, 3 Jul 2008 22:28:35 +0000 (+0100) Subject: [MIPS] Fix bug in atomic_sub_if_positive. X-Git-Tag: v2.6.26-rc9~59^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=50952026036c7b4212b90091bf23a264c0ccc1fb;p=linux-2.6 [MIPS] Fix bug in atomic_sub_if_positive. The branch optimization fixes in 2.6.21 introduced a bug in atomic_sub_if_positive that causes it to return even when the sc instruction fails. The result is that e.g. down_trylock becomes unreliable as the semaphore counter is not always decremented. Original MUA-shredded patch from Morten Larsen . Signed-off-by: Ralf Baechle --- diff --git a/include/asm-mips/atomic.h b/include/asm-mips/atomic.h index a798d6299a..1232be3885 100644 --- a/include/asm-mips/atomic.h +++ b/include/asm-mips/atomic.h @@ -283,10 +283,10 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v) " beqz %0, 2f \n" " subu %0, %1, %3 \n" " .set reorder \n" - "1: \n" " .subsection 2 \n" "2: b 1b \n" " .previous \n" + "1: \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter) @@ -664,10 +664,10 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v) " beqz %0, 2f \n" " dsubu %0, %1, %3 \n" " .set reorder \n" - "1: \n" " .subsection 2 \n" "2: b 1b \n" " .previous \n" + "1: \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter)