fixed issue of resetting and dropping the usb disk during usb access

linux/drivers/usb/musb/musb_host.c

@@ -407,11 +407,19 @@ static u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
 	 * ignore dma (various models),
 	 * leave toggle alone (may not have been saved yet)
 	 */
+#if NICHOLAS_ADD
+	csr |= MUSB_RXCSR_FLUSHFIFO;
+	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
+	csr &= ~(MUSB_RXCSR_H_REQPKT
+		| MUSB_RXCSR_H_AUTOREQ
+		| MUSB_RXCSR_AUTOCLEAR
+		| MUSB_RXCSR_RXPKTRDY);
+#else
 	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
 	csr &= ~(MUSB_RXCSR_H_REQPKT
 		| MUSB_RXCSR_H_AUTOREQ
 		| MUSB_RXCSR_AUTOCLEAR);
-
+#endif
 	/* write 2x to allow double buffering */
 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
@@ -928,7 +936,12 @@ finish:
 				csr = MUSB_RXCSR_H_WR_DATATOGGLE
 					| MUSB_RXCSR_H_DATATOGGLE;
 			else
+#if NICHOLAS_ADD
+				csr |= MUSB_RXCSR_CLRDATATOG;
+#else
 				csr = 0;
+#endif
+
 			if (qh->type == USB_ENDPOINT_XFER_INT)
 				csr |= MUSB_RXCSR_DISNYET;
 
@@ -1483,7 +1496,14 @@ done:
 				done = true;
 			if (!done) {
 				offset = qh->offset;
+#if NICHOLAS_ADD
+				if (can_bulk_split(musb, qh->type))
+					length = min((u32) hw_ep->max_packet_sz_tx, urb->transfer_buffer_length - offset);
+				else
+					length = min((u32) qh->maxpacket, urb->transfer_buffer_length - offset);
+#else
 				length = urb->transfer_buffer_length - offset;
+#endif
 				transfer_pending = true;
 			}
 		}
@@ -1781,6 +1801,13 @@ static int musb_rx_dma_in_inventra_cppi41(struct dma_controller *dma,
 	 * transfer_buffer_length needs to be
 	 * adjusted first...
 	 */
+
+#if NICHOLAS_ADD
+	//Nicholas fix bug
+	if(length > urb->transfer_buffer_length)
+		length = urb->transfer_buffer_length;
+#endif
+
 	done = dma->channel_program(channel, qh->maxpacket,
 				   channel->desired_mode,
 				   buf, length);
@@ -2050,10 +2077,16 @@ void musb_host_rx(struct musb *musb, u8 epnum)
 				urb->transfer_buffer_length);
 
 			if (musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh, urb,
-							   xfer_len, iso_err))
+							   xfer_len, iso_err)) {
 				goto finish;
-			else
+			}
+			else {
+#if NICHOLAS_ADD
+				dma = NULL;
+#else
 				dev_err(musb->controller, "error: rx_dma failed\n");
+#endif
+			}
 		}
 
 		if (!dma) {

linux/drivers/usb/musb/musbhsdma.c

@@ -51,7 +51,7 @@
 #define MUSB_HSDMA_BURSTMODE_INCR8	2
 #define MUSB_HSDMA_BURSTMODE_INCR16	3
 
-#define MUSB_HSDMA_CHANNELS		8
+#define MUSB_HSDMA_CHANNELS		4
 
 struct musb_dma_controller;
 
@@ -120,7 +120,7 @@ static struct dma_channel *dma_channel_allocate(struct dma_controller *c,
 			channel = &(musb_channel->channel);
 			channel->private_data = musb_channel;
 			channel->status = MUSB_DMA_STATUS_FREE;
-			channel->max_len = 0x400;
+			channel->max_len = 0x200;
 			/* Tx => mode 1; Rx => mode 0 */
 			channel->desired_mode = transmit;
 			channel->actual_len = 0;
@@ -191,6 +191,10 @@ static int dma_channel_program(struct dma_channel *channel,
 	struct musb_dma_controller *controller = musb_channel->controller;
 	struct musb *musb = controller->private_data;
 
+#if NICHOLAS_ADD
+	if(len <= 64)
+		return false;
+#endif
 	musb_dbg(musb, "ep%d-%s pkt_sz %d, dma_addr %pad length %d, mode %d",
 		musb_channel->epnum,
 		musb_channel->transmit ? "Tx" : "Rx",