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 <david.laight@xxxxxxxxxx>
---
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
--
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