2 files changed, 17 insertions, 0 deletions

diff --git a/drivers/usb/musb/musb_dma.h b/drivers/usb/musb/musb_dma.h
index 916065ba9e70..3a97c4e2d4f5 100644
--- a/drivers/usb/musb/musb_dma.h
+++ b/drivers/usb/musb/musb_dma.h
@@ -169,6 +169,9 @@ struct dma_controller {
                                                         dma_addr_t dma_addr,
                                                         u32 length);
         int                     (*channel_abort)(struct dma_channel *);
+        int                     (*is_compatible)(struct dma_channel *channel,
+                                                        u16 maxpacket,
+                                                        void *buf, u32 length);
 };
 
 /* called after channel_program(), may indicate a fault */
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 65775039d6b3..2fe304611dcf 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -100,11 +100,25 @@
 static inline void map_dma_buffer(struct musb_request *request,
                         struct musb *musb, struct musb_ep *musb_ep)
 {
+        int compatible = true;
+        struct dma_controller *dma = musb->dma_controller;
+
         request->map_state = UN_MAPPED;
 
         if (!is_dma_capable() || !musb_ep->dma)
                 return;
 
+        /* Check if DMA engine can handle this request.
+         * DMA code must reject the USB request explicitly.
+         * Default behaviour is to map the request.
+         */
+        if (dma->is_compatible)
+                compatible = dma->is_compatible(musb_ep->dma,
+                                musb_ep->packet_sz, request->request.buf,
+                                request->request.length);
+        if (!compatible)
+                return;
+
         if (request->request.dma == DMA_ADDR_INVALID) {
                 request->request.dma = dma_map_single(
                                 musb->controller,