diff --git a/sys/compat/linuxkpi/common/include/linux/dma-mapping.h b/sys/compat/linuxkpi/common/include/linux/dma-mapping.h
--- a/sys/compat/linuxkpi/common/include/linux/dma-mapping.h
+++ b/sys/compat/linuxkpi/common/include/linux/dma-mapping.h
@@ -97,12 +97,12 @@
 void *linuxkpi_dmam_alloc_coherent(struct device *dev, size_t size,
     dma_addr_t *dma_handle, gfp_t flag);
 dma_addr_t linux_dma_map_phys(struct device *dev, vm_paddr_t phys, size_t len);
-void linux_dma_unmap(struct device *dev, dma_addr_t dma_addr, size_t size);
+void linux_dma_unmap(struct device *dev, dma_addr_t dma_addr, size_t size, enum dma_data_direction);
 int linux_dma_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
-    int nents, enum dma_data_direction dir __unused,
+    int nents, enum dma_data_direction direction,
     unsigned long attrs __unused);
 void linux_dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
-    int nents __unused, enum dma_data_direction dir __unused,
+    int nents __unused, enum dma_data_direction direction,
     unsigned long attrs __unused);
 void linuxkpi_dma_sync(struct device *, dma_addr_t, size_t, bus_dmasync_op_t);
 
@@ -173,15 +173,17 @@
     dma_addr_t dma_addr)
 {
 
-	linux_dma_unmap(dev, dma_addr, size);
+	pr_debug("%s:%d: TODO DMA_NONE?\n", __func__, __LINE__);
+	linux_dma_unmap(dev, dma_addr, size, DMA_NONE);
 	kmem_free(cpu_addr, size);
 }
 
 static inline dma_addr_t
 dma_map_page_attrs(struct device *dev, struct page *page, size_t offset,
-    size_t size, enum dma_data_direction dir, unsigned long attrs)
+    size_t size, enum dma_data_direction direction, unsigned long attrs __unused)
 {
 
+	pr_debug("%s:%d: TODO dir %d\n", __func__, __LINE__, direction);
 	return (linux_dma_map_phys(dev, page_to_phys(page) + offset, size));
 }
 
@@ -197,6 +199,7 @@
     unsigned long offset, size_t size, enum dma_data_direction direction)
 {
 
+	pr_debug("%s:%d: TODO dir %d\n", __func__, __LINE__, direction);
 	return (linux_dma_map_phys(dev, page_to_phys(page) + offset, size));
 }
 
@@ -205,7 +208,7 @@
     enum dma_data_direction direction)
 {
 
-	linux_dma_unmap(dev, dma_address, size);
+	linux_dma_unmap(dev, dma_address, size, direction);
 }
 
 static inline void
@@ -267,24 +270,28 @@
 dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
     enum dma_data_direction direction)
 {
+	pr_debug("%s:%d: TODO dir %d\n", __func__, __LINE__, direction);
 }
 
 static inline void
 dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
     enum dma_data_direction direction)
 {
+	pr_debug("%s:%d: TODO dir %d\n", __func__, __LINE__, direction);
 }
 
 static inline void
 dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
-    unsigned long offset, size_t size, int direction)
+    unsigned long offset, size_t size, enum dma_data_direction direction)
 {
+	pr_debug("%s:%d: TODO dir %d\n", __func__, __LINE__, direction);
 }
 
 static inline void
 dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
-    unsigned long offset, size_t size, int direction)
+    unsigned long offset, size_t size, enum dma_data_direction direction)
 {
+	pr_debug("%s:%d: TODO dir %d\n", __func__, __LINE__, direction);
 }
 
 #define	DMA_MAPPING_ERROR	(~(dma_addr_t)0)
@@ -323,7 +330,7 @@
 {
 
 	dma_sync_single_for_cpu(dev, dma, size, direction);
-	linux_dma_unmap(dev, dma, size);
+	linux_dma_unmap(dev, dma, size, direction);
 }
 
 static inline size_t
diff --git a/sys/compat/linuxkpi/common/src/linux_pci.c b/sys/compat/linuxkpi/common/src/linux_pci.c
--- a/sys/compat/linuxkpi/common/src/linux_pci.c
+++ b/sys/compat/linuxkpi/common/src/linux_pci.c
@@ -1482,7 +1482,8 @@
 
 #if defined(__i386__) || defined(__amd64__) || defined(__aarch64__)
 void
-linux_dma_unmap(struct device *dev, dma_addr_t dma_addr, size_t len)
+linux_dma_unmap(struct device *dev, dma_addr_t dma_addr, size_t len,
+    enum dma_data_direction direction)
 {
 	struct linux_dma_priv *priv;
 	struct linux_dma_obj *obj;
@@ -1499,6 +1500,22 @@
 		return;
 	}
 	LINUX_DMA_PCTRIE_REMOVE(&priv->ptree, dma_addr);
+
+	switch (direction) {
+	case DMA_BIDIRECTIONAL:
+		bus_dmamap_sync(obj->dmat, obj->dmamap, BUS_DMASYNC_POSTREAD);
+		bus_dmamap_sync(obj->dmat, obj->dmamap, BUS_DMASYNC_PREREAD);
+		break;
+	case DMA_TO_DEVICE:
+		bus_dmamap_sync(obj->dmat, obj->dmamap, BUS_DMASYNC_POSTWRITE);
+		break;
+	case DMA_FROM_DEVICE:
+		bus_dmamap_sync(obj->dmat, obj->dmamap, BUS_DMASYNC_POSTREAD);
+		break;
+	default:
+		break;
+	}
+
 	bus_dmamap_unload(obj->dmat, obj->dmamap);
 	bus_dmamap_destroy(obj->dmat, obj->dmamap);
 	DMA_PRIV_UNLOCK(priv);
@@ -1507,7 +1524,8 @@
 }
 #else
 void
-linux_dma_unmap(struct device *dev, dma_addr_t dma_addr, size_t len)
+linux_dma_unmap(struct device *dev, dma_addr_t dma_addr, size_t len,
+    enum dma_data_direction direction)
 {
 }
 #endif