2 files changed, 55 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 4ed9f5f7a146..d64f5724bfc4 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -625,6 +625,36 @@ static inline u32 xhci_get_endpoint_type(struct usb_device *udev,
         return type;
 }
 
+/* Return the maximum endpoint service interval time (ESIT) payload.
+ * Basically, this is the maxpacket size, multiplied by the burst size
+ * and mult size.
+ */
+static inline u32 xhci_get_max_esit_payload(struct xhci_hcd *xhci,
+                struct usb_device *udev,
+                struct usb_host_endpoint *ep)
+{
+        int max_burst;
+        int max_packet;
+
+        /* Only applies for interrupt or isochronous endpoints */
+        if (usb_endpoint_xfer_control(&ep->desc) ||
+                        usb_endpoint_xfer_bulk(&ep->desc))
+                return 0;
+
+        if (udev->speed == USB_SPEED_SUPER) {
+                if (ep->ss_ep_comp)
+                        return ep->ss_ep_comp->desc.wBytesPerInterval;
+                xhci_warn(xhci, "WARN no SS endpoint companion descriptor.\n");
+                /* Assume no bursts, no multiple opportunities to send. */
+                return ep->desc.wMaxPacketSize;
+        }
+
+        max_packet = ep->desc.wMaxPacketSize & 0x3ff;
+        max_burst = (ep->desc.wMaxPacketSize & 0x1800) >> 11;
+        /* A 0 in max burst means 1 transfer per ESIT */
+        return max_packet * (max_burst + 1);
+}
+
 int xhci_endpoint_init(struct xhci_hcd *xhci,
                 struct xhci_virt_device *virt_dev,
                 struct usb_device *udev,
@@ -636,6 +666,7 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
         struct xhci_ring *ep_ring;
         unsigned int max_packet;
         unsigned int max_burst;
+        u32 max_esit_payload;
 
         ep_index = xhci_get_endpoint_index(&ep->desc);
         ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
@@ -703,6 +734,26 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
         default:
                 BUG();
         }
+        max_esit_payload = xhci_get_max_esit_payload(xhci, udev, ep);
+        ep_ctx->tx_info = MAX_ESIT_PAYLOAD_FOR_EP(max_esit_payload);
+
+        /*
+         * XXX no idea how to calculate the average TRB buffer length for bulk
+         * endpoints, as the driver gives us no clue how big each scatter gather
+         * list entry (or buffer) is going to be.
+         *
+         * For isochronous and interrupt endpoints, we set it to the max
+         * available, until we have new API in the USB core to allow drivers to
+         * declare how much bandwidth they actually need.
+         *
+         * Normally, it would be calculated by taking the total of the buffer
+         * lengths in the TD and then dividing by the number of TRBs in a TD,
+         * including link TRBs, No-op TRBs, and Event data TRBs.  Since we don't
+         * use Event Data TRBs, and we don't chain in a link TRB on short
+         * transfers, we're basically dividing by 1.
+         */
+        ep_ctx->tx_info |= AVG_TRB_LENGTH_FOR_EP(max_esit_payload);
+
         /* FIXME Debug endpoint context */
         return 0;
 }
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index e5eb09b2f38e..ea389e9a4931 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -609,6 +609,10 @@ struct xhci_ep_ctx {
 #define MAX_PACKET_MASK         (0xffff << 16)
 #define MAX_PACKET_DECODED(p)   (((p) >> 16) & 0xffff)
 
+/* tx_info bitmasks */
+#define AVG_TRB_LENGTH_FOR_EP(p)        ((p) & 0xffff)
+#define MAX_ESIT_PAYLOAD_FOR_EP(p)      (((p) & 0xffff) << 16)
+
 
 /**
  * struct xhci_input_control_context