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path: root/drivers/usb/host/xhci-mem.c
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Diffstat (limited to 'drivers/usb/host/xhci-mem.c')
-rw-r--r--drivers/usb/host/xhci-mem.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 4ed9f5f7a14..d64f5724bfc 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;
}