USB: centralize -EREMOTEIO handling

This patch (as969) continues the ongoing changes to the way HCDs
report URB statuses. The programming interface has been simplified by
making usbcore responsible for clearing urb->hcpriv and for setting
-EREMOTEIO status when an URB with the URB_SHORT_NOT_OK flag ends up
as a short transfer.

By moving the work out of the HCDs, this removes a fair amount of
repeated code.

Signed-off-by: Alan Stern <[e-mail]>
CC: David Brownell <[e-mail]>
CC: Olav Kongas <[e-mail]>
CC: Yoshihiro Shimoda <[e-mail]>
CC: Tony Olech <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/core/hcd.c

···
 	spin_unlock_irq(&hcd_root_hub_lock);
 	if (status)
 		return status;
+	urb->hcpriv = hcd;	/* Indicate it's queued */
 
 	cmd = (struct usb_ctrlrequest *) urb->setup_packet;
 	typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
···
 			hcd->poll_pending = 0;
 			hcd->status_urb = NULL;
 			urb->status = 0;
-			urb->hcpriv = NULL;
 			urb->actual_length = length;
 			memcpy(urb->transfer_buffer, buffer, length);
 
···
 			del_timer (&hcd->rh_timer);
 		if (urb == hcd->status_urb) {
 			hcd->status_urb = NULL;
-			urb->hcpriv = NULL;
 			usb_hcd_unlink_urb_from_ep(hcd, urb);
 
 			spin_unlock(&hcd_root_hub_lock);
···
 	if (unlikely(status)) {
 		usbmon_urb_submit_error(&hcd->self, urb, status);
 		unmap_urb_for_dma(hcd, urb);
+		urb->hcpriv = NULL;
 		INIT_LIST_HEAD(&urb->urb_list);
 		atomic_dec(&urb->use_count);
 		if (urb->reject)
···
 	unmap_urb_for_dma(hcd, urb);
 	usbmon_urb_complete (&hcd->self, urb);
 	usb_unanchor_urb(urb);
+	urb->hcpriv = NULL;
+	if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
+			urb->actual_length < urb->transfer_buffer_length &&
+			!urb->status))
+		urb->status = -EREMOTEIO;
 
 	/* pass ownership to the completion handler */
 	urb->complete (urb);

drivers/usb/gadget/dummy_hcd.c

···
 		 *
 		 * partially filling a buffer optionally blocks queue advances
 		 * (so completion handlers can clean up the queue) but we don't
-		 * need to emulate such data-in-flight.  so we only show part
-		 * of the URB_SHORT_NOT_OK effect: completion status.
+		 * need to emulate such data-in-flight.
 		 */
 		if (is_short) {
 			if (host_len == dev_len) {
···
 				if (dev_len > host_len)
 					maybe_set_status (urb, -EOVERFLOW);
 				else
-					maybe_set_status (urb,
-						(urb->transfer_flags
-							& URB_SHORT_NOT_OK)
-						? -EREMOTEIO : 0);
+					maybe_set_status (urb, 0);
 			} else if (!to_host) {
 				maybe_set_status (urb, 0);
 				if (host_len > dev_len)
···
 			continue;
 
 return_urb:
-		urb->hcpriv = NULL;
 		list_del (&urbp->urbp_list);
 		kfree (urbp);
 		if (ep)

drivers/usb/host/ehci-q.c

···
 	}
 
 	spin_lock (&urb->lock);
-	urb->hcpriv = NULL;
 	switch (urb->status) {
 	case -EINPROGRESS:		/* success */
 		urb->status = 0;
···
 		/* remove it from the queue */
 		spin_lock (&urb->lock);
 		qtd_copy_status (ehci, urb, qtd->length, token);
-		do_status = (urb->status == -EREMOTEIO)
-				&& usb_pipecontrol (urb->pipe);
+		if (unlikely(urb->status == -EREMOTEIO)) {
+			do_status = usb_pipecontrol(urb->pipe);
+			urb->status = 0;
+		}
 		spin_unlock (&urb->lock);
 
 		if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {

drivers/usb/host/isp116x-hcd.c

···
 {
 	unsigned i;
 
-	urb->hcpriv = NULL;
 	ep->error_count = 0;
 
 	if (usb_pipecontrol(urb->pipe))
···
 			if (PTD_GET_ACTIVE(ptd)
 			    || (cc != TD_CC_NOERROR && cc < 0x0E))
 				break;
-			if ((urb->transfer_flags & URB_SHORT_NOT_OK) &&
-					urb->actual_length <
-						urb->transfer_buffer_length)
-				status = -EREMOTEIO;
-			else
-				status = 0;
+			status = 0;
 			ep->nextpid = 0;
 			break;
 		default:

drivers/usb/host/ohci-q.c

···
 	// ASSERT (urb->hcpriv != 0);
 
 	urb_free_priv (ohci, urb->hcpriv);
-	urb->hcpriv = NULL;
 
 	spin_lock (&urb->lock);
 	if (likely (urb->status == -EINPROGRESS))
 		urb->status = 0;
-	/* report short control reads right even though the data TD always
-	 * has TD_R set.  (much simpler, but creates the 1-td limit.)
-	 */
-	if (unlikely (urb->transfer_flags & URB_SHORT_NOT_OK)
-			&& unlikely (usb_pipecontrol (urb->pipe))
-			&& urb->actual_length < urb->transfer_buffer_length
-			&& usb_pipein (urb->pipe)
-			&& urb->status == 0) {
-		urb->status = -EREMOTEIO;
-	}
 	spin_unlock (&urb->lock);
 
 	switch (usb_pipetype (urb->pipe)) {

drivers/usb/host/r8a66597-hcd.c

···
 
 		if (urb) {
 			urb->status = -ENODEV;
-			urb->hcpriv = NULL;
 			usb_hcd_unlink_urb_from_ep(r8a66597_to_hcd(r8a66597),
 					urb);
 
···
 		if (usb_pipeisoc(urb->pipe))
 			urb->start_frame = r8a66597_get_frame(hcd);
 
-		urb->hcpriv = NULL;
 		usb_hcd_unlink_urb_from_ep(r8a66597_to_hcd(r8a66597), urb);
 
 		spin_unlock(&r8a66597->lock);
···
 		td->zero_packet = 1;
 	if (rcv_len < bufsize) {
 		td->short_packet = 1;
-		if (urb->transfer_buffer_length != urb->actual_length &&
-		    urb->transfer_flags & URB_SHORT_NOT_OK)
-			status = -EREMOTEIO;
 	}
 	if (usb_pipeisoc(urb->pipe)) {
 		urb->iso_frame_desc[td->iso_cnt].actual_length = size;
···
 	}
 
 	/* check transfer finish */
-	if (check_transfer_finish(td, urb)) {
+	if (finish || check_transfer_finish(td, urb)) {
 		pipe_stop(r8a66597, td->pipe);
 		pipe_irq_disable(r8a66597, pipenum);
 		finish = 1;

drivers/usb/host/sl811-hcd.c

···
 	spin_lock(&urb->lock);
 	if (urb->status == -EINPROGRESS)
 		urb->status = status;
-	urb->hcpriv = NULL;
 	spin_unlock(&urb->lock);
 
 	usb_hcd_unlink_urb_from_ep(sl811_to_hcd(sl811), urb);
···
 			sl811_read_buf(sl811, SL811HS_PACKET_BUF(bank == 0),
 					buf, len);
 			usb_dotoggle(udev, ep->epnum, 0);
-			if (urb->actual_length == urb->transfer_buffer_length)
+			if (urb->actual_length == urb->transfer_buffer_length
+					|| len < ep->maxpacket)
 				urbstat = 0;
-			else if (len < ep->maxpacket) {
-				if (urb->transfer_flags & URB_SHORT_NOT_OK)
-					urbstat = -EREMOTEIO;
-				else
-					urbstat = 0;
-			}
-			if (usb_pipecontrol(urb->pipe)
-					&& (urbstat == -EREMOTEIO
-						|| urbstat == 0)) {
+			if (usb_pipecontrol(urb->pipe) && urbstat == 0) {
 
 				/* NOTE if the status stage STALLs (why?),
 				 * this reports the wrong urb status.

drivers/usb/host/u132-hcd.c

···
         struct usb_hcd *hcd = u132_to_hcd(u132);
         urb->error_count = 0;
         urb->status = status;
-        urb->hcpriv = NULL;
         spin_lock_irqsave(&endp->queue_lock.slock, irqs);
 	usb_hcd_unlink_urb_from_ep(hcd, urb);
         endp->queue_next += 1;
···
         struct usb_hcd *hcd = u132_to_hcd(u132);
         urb->error_count = 0;
         urb->status = status;
-        urb->hcpriv = NULL;
         spin_lock_irqsave(&endp->queue_lock.slock, irqs);
 	usb_hcd_unlink_urb_from_ep(hcd, urb);
         endp->queue_next += 1;
···
                         list_del(scan);
                         endp->queue_size -= 1;
                         urb->error_count = 0;
-                        urb->hcpriv = NULL;
                         usb_hcd_giveback_urb(hcd, urb);
                         return 0;
                 } else
···
                         endp->edset_flush = 1;
                         u132_endp_queue_work(u132, endp, 0);
                         spin_unlock_irqrestore(&endp->queue_lock.slock, irqs);
-                        urb->hcpriv = NULL;
                         return 0;
                 } else {
                         spin_unlock_irqrestore(&endp->queue_lock.slock, irqs);
···
                                         irqs);
                                 kfree(urbq);
                         } urb->error_count = 0;
-                        urb->hcpriv = NULL;
                         usb_hcd_giveback_urb(hcd, urb);
                         return 0;
                 } else if (list_empty(&endp->urb_more)) {

drivers/usb/host/uhci-q.c

···
 		uhci_free_td(uhci, td);
 	}
 
-	urbp->urb->hcpriv = NULL;
 	kmem_cache_free(uhci_up_cachep, urbp);
 }
 
···
 		 * unlinked first.  Regardless, don't confuse people with a
 		 * negative length. */
 		urb->actual_length = max(urb->actual_length, 0);
-
-		/* Report erroneous short transfers */
-		if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
-				urb->actual_length <
-					urb->transfer_buffer_length &&
-				urb->status == 0))
-			urb->status = -EREMOTEIO;
 	}
 
 	/* When giving back the first URB in an Isochronous queue,