Staging: Merge 2.6.37-rc5 into staging-next

This was done to handle a number of conflicts in the batman-adv
and winbond drivers properly.  It also now allows us to fix up the sysfs
attributes properly that were not in the .37 release due to them being
only in this tree at the time.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 18 insertions, 11 deletions

diff --git a/arch/tile/lib/spinlock_32.c b/arch/tile/lib/spinlock_32.c
index 485e24d62c6..5cd1c4004ec 100644
--- a/arch/tile/lib/spinlock_32.c
+++ b/arch/tile/lib/spinlock_32.c
@@ -167,23 +167,30 @@ void arch_write_lock_slow(arch_rwlock_t *rwlock, u32 val)
          * when we compare them.
          */
         u32 my_ticket_;
+        u32 iterations = 0;
 
-        /* Take out the next ticket; this will also stop would-be readers. */
-        if (val & 1)
-                val = get_rwlock(rwlock);
-        rwlock->lock = __insn_addb(val, 1 << WR_NEXT_SHIFT);
+        /*
+         * Wait until there are no readers, then bump up the next
+         * field and capture the ticket value.
+         */
+        for (;;) {
+                if (!(val & 1)) {
+                        if ((val >> RD_COUNT_SHIFT) == 0)
+                                break;
+                        rwlock->lock = val;
+                }
+                delay_backoff(iterations++);
+                val = __insn_tns((int *)&rwlock->lock);
+        }
 
-        /* Extract my ticket value from the original word. */
+        /* Take out the next ticket and extract my ticket value. */
+        rwlock->lock = __insn_addb(val, 1 << WR_NEXT_SHIFT);
         my_ticket_ = val >> WR_NEXT_SHIFT;
 
-        /*
-         * Wait until the "current" field matches our ticket, and
-         * there are no remaining readers.
-         */
+        /* Wait until the "current" field matches our ticket. */
         for (;;) {
                 u32 curr_ = val >> WR_CURR_SHIFT;
-                u32 readers = val >> RD_COUNT_SHIFT;
-                u32 delta = ((my_ticket_ - curr_) & WR_MASK) + !!readers;
+                u32 delta = ((my_ticket_ - curr_) & WR_MASK);
                 if (likely(delta == 0))
                         break;