v1.0 hosts need the td_size set to the number of messages (including the final short one) that need to be sent to complete the transfer after all the full-sized ones for the current TRB have been sent.
The code in xhci_v1_0_td_remainder() carefully copies the algorithm from the documentation, but the value can be calculated much more easily. Signed-off-by: David Laight <[email protected]> --- drivers/usb/host/xhci-ring.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index bf9a20f..afd8eeb 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -3272,9 +3272,9 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, unsigned int num_trbs; struct urb_priv *urb_priv; struct scatterlist *sg; - u32 trb_buff_len, this_sg_len, running_total; + u32 trb_buff_len, this_sg_len; u32 len_left; - unsigned int total_packet_count; + u32 td_residue, max_packet; u32 trb_type_flags; u64 addr; int ret; @@ -3287,8 +3287,19 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, return -EINVAL; num_trbs = count_sg_trbs_needed(ep_ring, urb); - total_packet_count = DIV_ROUND_UP(urb->transfer_buffer_length, - usb_endpoint_maxp(&urb->ep->desc)); + + /* + * For v1.0 endpoints we need to calculate the number of packets + * required to complete the request. + * The code here is equivalent to the calculations in section 4.11.2.4 + * + * td_residue is set so that td_residue/max_packet is the number of + * packets required to send the data after the current partial + * transfer(s) have completed. + */ + max_packet = GET_MAX_PACKET(usb_endpoint_maxp(&urb->ep->desc)); + td_residue = urb->transfer_buffer_length; + td_residue = ALIGN(td_residue, max_packet) + max_packet - 1; ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index, urb->stream_id, @@ -3313,7 +3324,6 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, if (usb_urb_dir_in(urb)) trb_type_flags |= TRB_ISP; - running_total = 0; len_left = urb->transfer_buffer_length; sg = urb->sg; @@ -3323,7 +3333,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, /* Queue the first TRB, even if it's zero-length */ for (;;) { u32 length_field = 0; - u32 remainder = 0; + u32 td_size = 0; /* * How much data is in the TRB? * @@ -3342,9 +3352,11 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, urb_priv->td[0]->last_trb = ep_ring->enqueue; /* Request interrupt and clear chain */ trb_type_flags ^= TRB_IOC | TRB_CHAIN; + td_residue = 0; } else { if (trb_buff_len == 0) goto next_frag; + td_residue -= trb_buff_len; } /* Set the correct cycle bit (inverted for first TRB). */ @@ -3352,14 +3364,13 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, /* Set the TRB length, TD size, and interrupter fields. */ if (xhci->hci_version < 0x100) { - remainder = xhci_td_remainder(len_left); + td_size = xhci_td_remainder(len_left); } else { - remainder = xhci_v1_0_td_remainder(running_total, - trb_buff_len, total_packet_count, urb, - trb_buff_len != len_left); + td_size = min_t(u32, td_residue / max_packet, 31) << 17; } + length_field = TRB_LEN(trb_buff_len) | - remainder | + td_size | TRB_INTR_TARGET(0); queue_trb(xhci, ep_ring, false, @@ -3375,7 +3386,6 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, /* We want the current cycle in subsequent TRB */ trb_type_flags &= ~TRB_CYCLE; - running_total += trb_buff_len; len_left -= trb_buff_len; /* Advance source data pointer */ -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
