diff options
Diffstat (limited to 'drivers/usb/host/xhci.c')
| -rw-r--r-- | drivers/usb/host/xhci.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 89ac4853409..f5e0b00cbb8 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -916,6 +916,47 @@ dying: return -ESHUTDOWN; } +/* Get the right ring for the given URB. + * If the endpoint supports streams, boundary check the URB's stream ID. + * If the endpoint doesn't support streams, return the singular endpoint ring. + */ +static struct xhci_ring *xhci_urb_to_transfer_ring(struct xhci_hcd *xhci, + struct urb *urb) +{ + unsigned int slot_id; + unsigned int ep_index; + unsigned int stream_id; + struct xhci_virt_ep *ep; + + slot_id = urb->dev->slot_id; + ep_index = xhci_get_endpoint_index(&urb->ep->desc); + stream_id = urb->stream_id; + ep = &xhci->devs[slot_id]->eps[ep_index]; + /* Common case: no streams */ + if (!(ep->ep_state & EP_HAS_STREAMS)) + return ep->ring; + + if (stream_id == 0) { + xhci_warn(xhci, + "WARN: Slot ID %u, ep index %u has streams, " + "but URB has no stream ID.\n", + slot_id, ep_index); + return NULL; + } + + if (stream_id < ep->stream_info->num_streams) + return ep->stream_info->stream_rings[stream_id]; + + xhci_warn(xhci, + "WARN: Slot ID %u, ep index %u has " + "stream IDs 1 to %u allocated, " + "but stream ID %u is requested.\n", + slot_id, ep_index, + ep->stream_info->num_streams - 1, + stream_id); + return NULL; +} + /* * Remove the URB's TD from the endpoint ring. This may cause the HC to stop * USB transfers, potentially stopping in the middle of a TRB buffer. The HC |