diff options
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index b2d654b7477e..54139a2f06ce 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2684,6 +2684,10 @@ static u32 xhci_v1_0_td_remainder(int running_total, int trb_buff_len, { int packets_transferred; + /* One TRB with a zero-length data packet. */ + if (running_total == 0 && trb_buff_len == 0) + return 0; + /* All the TRB queueing functions don't count the current TRB in * running_total. */ @@ -3125,20 +3129,15 @@ static int count_isoc_trbs_needed(struct xhci_hcd *xhci, struct urb *urb, int i) { int num_trbs = 0; - u64 addr, td_len, running_total; + u64 addr, td_len; addr = (u64) (urb->transfer_dma + urb->iso_frame_desc[i].offset); td_len = urb->iso_frame_desc[i].length; - running_total = TRB_MAX_BUFF_SIZE - (addr & (TRB_MAX_BUFF_SIZE - 1)); - running_total &= TRB_MAX_BUFF_SIZE - 1; - if (running_total != 0) - num_trbs++; - - while (running_total < td_len) { + num_trbs = DIV_ROUND_UP(td_len + (addr & (TRB_MAX_BUFF_SIZE - 1)), + TRB_MAX_BUFF_SIZE); + if (num_trbs == 0) num_trbs++; - running_total += TRB_MAX_BUFF_SIZE; - } return num_trbs; } @@ -3250,9 +3249,11 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 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)); + /* 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, |