blackfin: bf561: forgot CSYNC in get_core_lock_noflush

SMP kgdb runs into dead loop without this CSYNC when one core single
steps over get_core_lock_noflush and the other executes get_core_lock
as a slave node.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/blackfin/mach-bf561/atomic.S b/arch/blackfin/mach-bf561/atomic.S
index 52d6f73fcced..2a08df8e8c4c 100644
--- a/arch/blackfin/mach-bf561/atomic.S
+++ b/arch/blackfin/mach-bf561/atomic.S
@@ -72,6 +72,13 @@ ENTRY(_get_core_lock_noflush)
         SSYNC(r2);
         jump .Lretry_corelock_noflush
 .Ldone_corelock_noflush:
+        /*
+         * SMP kgdb runs into dead loop without NOP here, when one core
+         * single steps over get_core_lock_noflush and the other executes
+         * get_core_lock as a slave node.
+         */
+        nop;
+        CSYNC(r2);
         rts;
 ENDPROC(_get_core_lock_noflush)