xhci: cleanup isoc tranfers queuing code

BugLink: http://bugs.launchpad.net/bugs/1519623

Clean up xhci_queue_isoc_tx() and helpers to prepare them for USB 3.1 and
xhci 1.1 isoc TRB changes.

Only functional change is adding xhci version 1.1 to the BEI flag check
toghether with xhci version 1.0. Both versions behave the same.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 09c352ed)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/usb/host/xhci-ring.c

@@ -3552,12 +3552,11 @@ static int count_isoc_trbs_needed(struct xhci_hcd *xhci,
  * zero.  Only xHCI 1.0 host controllers support this field.
  */
 static unsigned int xhci_get_burst_count(struct xhci_hcd *xhci,
-		struct usb_device *udev,
 		struct urb *urb, unsigned int total_packet_count)
 {
 	unsigned int max_burst;
 
-	if (xhci->hci_version < 0x100 || udev->speed < USB_SPEED_SUPER)
+	if (xhci->hci_version < 0x100 || urb->dev->speed < USB_SPEED_SUPER)
 		return 0;
 
 	max_burst = urb->ep->ss_ep_comp.bMaxBurst;
@@ -3573,7 +3572,6 @@ static unsigned int xhci_get_burst_count(struct xhci_hcd *xhci,
  * contain 1 to (bMaxBurst + 1) packets.
  */
 static unsigned int xhci_get_last_burst_packet_count(struct xhci_hcd *xhci,
-		struct usb_device *udev,
 		struct urb *urb, unsigned int total_packet_count)
 {
 	unsigned int max_burst;
@@ -3582,9 +3580,7 @@ static unsigned int xhci_get_last_burst_packet_count(struct xhci_hcd *xhci,
 	if (xhci->hci_version < 0x100)
 		return 0;
 
-	switch (udev->speed) {
-	case USB_SPEED_SUPER_PLUS:
-	case USB_SPEED_SUPER:
+	if (urb->dev->speed >= USB_SPEED_SUPER) {
 		/* bMaxBurst is zero based: 0 means 1 packet per burst */
 		max_burst = urb->ep->ss_ep_comp.bMaxBurst;
 		residue = total_packet_count % (max_burst + 1);
@@ -3594,11 +3590,10 @@ static unsigned int xhci_get_last_burst_packet_count(struct xhci_hcd *xhci,
 		if (residue == 0)
 			return max_burst;
 		return residue - 1;
-	default:
-		if (total_packet_count == 0)
-			return 0;
-		return total_packet_count - 1;
 	}
+	if (total_packet_count == 0)
+		return 0;
+	return total_packet_count - 1;
 }
 
 /*
@@ -3709,6 +3704,7 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 	int i, j;
 	bool more_trbs_coming;
 	struct xhci_virt_ep *xep;
+	int frame_id;
 
 	xep = &xhci->devs[slot_id]->eps[ep_index];
 	ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
@@ -3718,33 +3714,31 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 		xhci_dbg(xhci, "Isoc URB with zero packets?\n");
 		return -EINVAL;
 	}
-
 	start_addr = (u64) urb->transfer_dma;
 	start_trb = &ep_ring->enqueue->generic;
 	start_cycle = ep_ring->cycle_state;
 
 	urb_priv = urb->hcpriv;
-	/* Queue the first TRB, even if it's zero-length */
+	/* Queue the TRBs for each TD, even if they are zero-length */
 	for (i = 0; i < num_tds; i++) {
-		unsigned int total_packet_count;
-		unsigned int burst_count;
-		unsigned int residue;
+		unsigned int total_pkt_count, max_pkt;
+		unsigned int burst_count, last_burst_pkt_count;
+		u32 sia_frame_id;
 
 		first_trb = true;
 		running_total = 0;
 		addr = start_addr + urb->iso_frame_desc[i].offset;
 		td_len = urb->iso_frame_desc[i].length;
 		td_remain_len = td_len;
-		total_packet_count = DIV_ROUND_UP(td_len,
-				GET_MAX_PACKET(
-					usb_endpoint_maxp(&urb->ep->desc)));
+		max_pkt = GET_MAX_PACKET(usb_endpoint_maxp(&urb->ep->desc));
+		total_pkt_count = DIV_ROUND_UP(td_len, max_pkt);
+
 		/* A zero-length transfer still involves at least one packet. */
-		if (total_packet_count == 0)
-			total_packet_count++;
-		burst_count = xhci_get_burst_count(xhci, urb->dev, urb,
-				total_packet_count);
-		residue = xhci_get_last_burst_packet_count(xhci,
-				urb->dev, urb, total_packet_count);
+		if (total_pkt_count == 0)
+			total_pkt_count++;
+		burst_count = xhci_get_burst_count(xhci, urb, total_pkt_count);
+		last_burst_pkt_count = xhci_get_last_burst_packet_count(xhci,
+							urb, total_pkt_count);
 
 		trbs_per_td = count_isoc_trbs_needed(xhci, urb, i);
 
@@ -3755,68 +3749,55 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 				return ret;
 			goto cleanup;
 		}
-
 		td = urb_priv->td[i];
+
+		/* use SIA as default, if frame id is used overwrite it */
+		sia_frame_id = TRB_SIA;
+		if (!(urb->transfer_flags & URB_ISO_ASAP) &&
+		    HCC_CFC(xhci->hcc_params)) {
+			frame_id = xhci_get_isoc_frame_id(xhci, urb, i);
+			if (frame_id >= 0)
+				sia_frame_id = TRB_FRAME_ID(frame_id);
+		}
+		/*
+		 * Set isoc specific data for the first TRB in a TD.
+		 * Prevent HW from getting the TRBs by keeping the cycle state
+		 * inverted in the first TDs isoc TRB.
+		 */
+		field = TRB_TBC(burst_count) |
+			TRB_TYPE(TRB_ISOC) |
+			TRB_TLBPC(last_burst_pkt_count) |
+			sia_frame_id |
+			(i ? ep_ring->cycle_state : !start_cycle);
+
+		/* fill the rest of the TRB fields, and remaining normal TRBs */
 		for (j = 0; j < trbs_per_td; j++) {
-			int frame_id = 0;
 			u32 remainder = 0;
-			field = 0;
-
-			if (first_trb) {
-				field = TRB_TBC(burst_count) |
-					TRB_TLBPC(residue);
-				/* Queue the isoc TRB */
-				field |= TRB_TYPE(TRB_ISOC);
-
-				/* Calculate Frame ID and SIA fields */
-				if (!(urb->transfer_flags & URB_ISO_ASAP) &&
-						HCC_CFC(xhci->hcc_params)) {
-					frame_id = xhci_get_isoc_frame_id(xhci,
-									  urb,
-									  i);
-					if (frame_id >= 0)
-						field |= TRB_FRAME_ID(frame_id);
-					else
-						field |= TRB_SIA;
-				} else
-					field |= TRB_SIA;
-
-				if (i == 0) {
-					if (start_cycle == 0)
-						field |= 0x1;
-				} else
-					field |= ep_ring->cycle_state;
-				first_trb = false;
-			} else {
-				/* Queue other normal TRBs */
-				field |= TRB_TYPE(TRB_NORMAL);
-				field |= ep_ring->cycle_state;
-			}
+
+			/* only first TRB is isoc, overwrite otherwise */
+			if (!first_trb)
+				field = TRB_TYPE(TRB_NORMAL) |
+					ep_ring->cycle_state;
+			first_trb = false;
 
 			/* Only set interrupt on short packet for IN EPs */
 			if (usb_urb_dir_in(urb))
 				field |= TRB_ISP;
 
-			/* Chain all the TRBs together; clear the chain bit in
-			 * the last TRB to indicate it's the last TRB in the
-			 * chain.
-			 */
+			/* Set the chain bit for all except the last TRB  */
 			if (j < trbs_per_td - 1) {
-				field |= TRB_CHAIN;
 				more_trbs_coming = true;
+				field |= TRB_CHAIN;
 			} else {
+				more_trbs_coming = false;
 				td->last_trb = ep_ring->enqueue;
 				field |= TRB_IOC;
-				if (xhci->hci_version == 0x100 &&
-						!(xhci->quirks &
-							XHCI_AVOID_BEI)) {
-					/* Set BEI bit except for the last td */
-					if (i < num_tds - 1)
-						field |= TRB_BEI;
-				}
-				more_trbs_coming = false;
+				/* set BEI, except for the last TD */
+				if (xhci->hci_version >= 0x100 &&
+				    !(xhci->quirks & XHCI_AVOID_BEI) &&
+				    i < num_tds - 1)
+					field |= TRB_BEI;
 			}
-
 			/* Calculate TRB length */
 			trb_buff_len = TRB_MAX_BUFF_SIZE -
 				(addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));