From: Chris Snook <[EMAIL PROTECTED]>
Make atomic_read() volatile on v850. This ensures that busy-waiting
for an interrupt handler to change an atomic_t won't get compiled to an
infinite loop, consistent with SMP architectures.
Signed-off-by: Chris Snook <[EMAIL PROTECTED]>
--- linux-2.6.23-rc2-orig/include/asm-v850/atomic.h 2007-07-08
19:32:17.000000000 -0400
+++ linux-2.6.23-rc2/include/asm-v850/atomic.h 2007-08-09 07:50:15.000000000
-0400
@@ -27,7 +27,11 @@ typedef struct { int counter; } atomic_t
#ifdef __KERNEL__
-#define atomic_read(v) ((v)->counter)
+/*
+ * Casting to volatile here minimizes the need for barriers,
+ * without having to declare the type itself as volatile.
+ */
+#define atomic_read(v) (*(volatile int *)&(v)->counter)
#define atomic_set(v,i) (((v)->counter) = (i))
static inline int atomic_add_return (int i, volatile atomic_t *v)
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
