USB: musb: allow unaligned memory data transfers

Commit Message

vikram pandita Jan. 12, 2010, 3:42 p.m. UTC

None

Patch

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index cbcf14a..7ad3571 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -681,8 +681,15 @@  static void rxstate(struct musb *musb, struct musb_request *req)
 							transfer_size);
 				}
 
-				if (use_dma)
+				if (use_dma) {
 					return;
+				} else {
+					/* Need to clear DMAENAB for the
+					 * backup PIO mode transfer to work
+					 */
+					csr &= ~MUSB_RXCSR_DMAENAB;
+					musb_writew(epio, MUSB_RXCSR, csr);
+				}
 			}
 #endif	/* Mentor's DMA */
 
diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c
index a237550..f118ae2 100644
--- a/drivers/usb/musb/musbhsdma.c
+++ b/drivers/usb/musb/musbhsdma.c
@@ -166,6 +166,8 @@  static int dma_channel_program(struct dma_channel *channel,
 				dma_addr_t dma_addr, u32 len)
 {
 	struct musb_dma_channel *musb_channel = channel->private_data;
+	struct musb_dma_controller *controller = musb_channel->controller;
+	struct musb *musb = controller->private_data;
 
 	DBG(2, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n",
 		musb_channel->epnum,
@@ -175,6 +177,15 @@  static int dma_channel_program(struct dma_channel *channel,
 	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
 		channel->status == MUSB_DMA_STATUS_BUSY);
 
+	/* On MUSB:RTL1.8 and above, DMA has to be word aligned */
+	if ((dma_addr % 4) &&
+		(musb->hwvers >= MUSB_HWVERS_1800)) {
+		/* Fail DMA for unaligned buffers:
+		 * Use PIO for such buffers
+		 */
+		return false;
+	}
+
 	channel->actual_len = 0;
 	musb_channel->start_addr = dma_addr;
 	musb_channel->len = len;