1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 28e743888402..20c1332a0018 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -90,10 +90,11 @@ void of_dma_configure(struct device *dev, struct device_node *np)
         struct iommu_ops *iommu;
 
         /*
-         * Set default dma-mask to 32 bit.  Drivers are expected to setup
-         * the correct supported dma_mask.
+         * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
+         * setup the correct supported mask.
          */
-        dev->coherent_dma_mask = DMA_BIT_MASK(32);
+        if (!dev->coherent_dma_mask)
+                dev->coherent_dma_mask = DMA_BIT_MASK(32);
 
         /*
          * Set it to coherent_dma_mask by default if the architecture
@@ -128,6 +129,15 @@ void of_dma_configure(struct device *dev, struct device_node *np)
 
         dev->dma_pfn_offset = offset;
 
+        /*
+         * Limit coherent and dma mask based on size and default mask
+         * set by the driver.
+         */
+        dev->coherent_dma_mask = min(dev->coherent_dma_mask,
+                                     DMA_BIT_MASK(ilog2(dma_addr + size)));
+        *dev->dma_mask = min((*dev->dma_mask),
+                             DMA_BIT_MASK(ilog2(dma_addr + size)));
+
         coherent = of_dma_is_coherent(np);
         dev_dbg(dev, "device is%sdma coherent\n",
                 coherent ? " " : " not ");