diff options
Diffstat (limited to 'drivers/usb/host/xhci-ring.c')
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 27d690d..cc59632 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -3123,6 +3123,27 @@ static int count_isoc_trbs_needed(struct xhci_hcd *xhci, return num_trbs; } +/* + * The transfer burst count field of the isochronous TRB defines the number of + * bursts that are required to move all packets in this TD. Only SuperSpeed + * devices can burst up to bMaxBurst number of packets per service interval. + * This field is zero based, meaning a value of zero in the field means one + * burst. Basically, for everything but SuperSpeed devices, this field will be + * 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) + return 0; + + max_burst = urb->ep->ss_ep_comp.bMaxBurst; + return roundup(total_packet_count, max_burst + 1) - 1; +} + /* This is for isoc transfer */ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags, struct urb *urb, int slot_id, unsigned int ep_index) @@ -3164,14 +3185,18 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags, /* Queue the first TRB, even if it's zero-length */ for (i = 0; i < num_tds; i++) { unsigned int total_packet_count; + unsigned int burst_count; 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; + /* FIXME: Ignoring zero-length packets, can those happen? */ total_packet_count = roundup(td_len, le16_to_cpu(urb->ep->desc.wMaxPacketSize)); + burst_count = xhci_get_burst_count(xhci, urb->dev, urb, + total_packet_count); trbs_per_td = count_isoc_trbs_needed(xhci, urb, i); @@ -3185,7 +3210,7 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags, for (j = 0; j < trbs_per_td; j++) { u32 remainder = 0; - field = 0; + field = TRB_TBC(burst_count); if (first_trb) { /* Queue the isoc TRB */ |