dma: of-dma: protect list write operation by spin_lock

It's possible to have an inconsistency in the list due to unprotected operation
on it. The patch adds a proper locking on the list operation.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index 583e50e3d47c..69d04d28b1ef 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -118,7 +118,9 @@ int of_dma_controller_register(struct device_node *np,
         ofdma->use_count = 0;
 
         /* Now queue of_dma controller structure in list */
+        spin_lock(&of_dma_lock);
         list_add_tail(&ofdma->of_dma_controllers, &of_dma_list);
+        spin_unlock(&of_dma_lock);
 
         return 0;
 }