[PATCH] USB gadget: net2280 controller updates

A variety of fixes:

    - Resolves some problems with DMA chaining.  It should stream
      a lot better now; but not all the funky cases are handled yet.

    - Now "use_dma_chaining" is a module parameter not a #define.
      It also defaults to false.  Some gadget drivers will work fine
      with this enabled, getting some IRQ reduction and increased
      I/O parallelism (given deep I/O queues); others won't.

    - Handle isochronous transfers (from Mark Huang at Broadcom)

    - Some of the chiprev 0100 workarounds weren't quite right.
      Neither were buffer allocations on dma-incoherent systems.

    - Handle bulk endpoint halts better, for file_storage gadget driver.

    - Handle the hardware device status bits better:
        * selfpowered by default, clearable with the API;
        * remote wakeup disabled by default, host must enable it.

    - Fix a shutdown problem seen in some statically linked configs.

Needed to use the new file_storage gadget without disabling DMA.

drivers/usb/gadget/net2280.h

@@ -520,6 +520,7 @@ struct net2280_ep {
 	unsigned				num : 8,
 						fifo_size : 12,
 						in_fifo_validate : 1,
+						out_overflow : 1,
 						stopped : 1,
 						is_in : 1,
 						is_iso : 1;
@@ -529,6 +530,7 @@ static inline void allow_status (struct net2280_ep *ep)
 {
 	/* ep0 only */
 	writel (  (1 << CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE)
+		| (1 << CLEAR_NAK_OUT_PACKETS)
 		| (1 << CLEAR_NAK_OUT_PACKETS_MODE)
 		, &ep->regs->ep_rsp);
 	ep->stopped = 1;
@@ -546,7 +548,6 @@ struct net2280_request {
 	dma_addr_t			td_dma;
 	struct list_head		queue;
 	unsigned			mapped : 1,
-					dma_done : 1,
 					valid : 1;
 };
 
@@ -559,8 +560,7 @@ struct net2280 {
 	unsigned			enabled : 1,
 					protocol_stall : 1,
 					got_irq : 1,
-					region : 1,
-					selfpowered : 1;
+					region : 1;
 	u16				chiprev;
 
 	/* pci state used to access those endpoints */