1 files changed, 8 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/fsl_rmu.c b/arch/powerpc/sysdev/fsl_rmu.c
index ab7a74c75be8..88b35a3dcdc5 100644
--- a/arch/powerpc/sysdev/fsl_rmu.c
+++ b/arch/powerpc/sysdev/fsl_rmu.c
@@ -104,6 +104,8 @@
 
 #define DOORBELL_MESSAGE_SIZE   0x08
 
+static DEFINE_SPINLOCK(fsl_rio_doorbell_lock);
+
 struct rio_msg_regs {
         u32 omr;
         u32 osr;
@@ -626,9 +628,13 @@ err_out:
 int fsl_rio_doorbell_send(struct rio_mport *mport,
                                 int index, u16 destid, u16 data)
 {
+        unsigned long flags;
+
         pr_debug("fsl_doorbell_send: index %d destid %4.4x data %4.4x\n",
                  index, destid, data);
 
+        spin_lock_irqsave(&fsl_rio_doorbell_lock, flags);
+
         /* In the serial version silicons, such as MPC8548, MPC8641,
          * below operations is must be.
          */
@@ -638,6 +644,8 @@ int fsl_rio_doorbell_send(struct rio_mport *mport,
         out_be32(&dbell->dbell_regs->oddatr, (index << 20) | data);
         out_be32(&dbell->dbell_regs->odmr, 0x00000001);
 
+        spin_unlock_irqrestore(&fsl_rio_doorbell_lock, flags);
+
         return 0;
 }