The TRB type and flags are the same for all the TRB expect the first
(which needs the opposite value of TRB_CYCLE) and the last (which
needs TRB_CHAIN clear and TRB_IOC set).
So move the code that sets it up outside the loop.
Signed-off-by: David Laight <david.laight@xxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 48 +++++++++++++++++++++-----------------------
1 file changed, 23 insertions(+), 25 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index a9cf058..51cc8a6 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3276,7 +3276,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
int trb_buff_len, this_sg_len, running_total;
int len_left;
unsigned int total_packet_count;
- bool first_trb;
+ u32 trb_type_flags;
u64 addr;
int ret;
@@ -3307,6 +3307,14 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
start_trb = &ep_ring->enqueue->generic;
start_cycle = ep_ring->cycle_state;
+ trb_type_flags = TRB_CHAIN | TRB_TYPE(TRB_NORMAL);
+ /* To avoid changing TRB_CYCLE on the first TRB we set it here */
+ trb_type_flags |= TRB_CYCLE;
+
+ /* Set interrupt on short packet for IN endpoints */
+ if (usb_urb_dir_in(urb))
+ trb_type_flags |= TRB_ISP;
+
running_total = 0;
len_left = urb->transfer_buffer_length;
/*
@@ -3326,39 +3334,26 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
if (trb_buff_len > urb->transfer_buffer_length)
trb_buff_len = urb->transfer_buffer_length;
- first_trb = true;
/* Queue the first TRB, even if it's zero-length */
for (;;) {
- u32 field = 0;
u32 length_field = 0;
u32 remainder = 0;
- /* Don't change the cycle bit of the first TRB until later */
- if (first_trb) {
- first_trb = false;
- if (start_cycle == 0)
- field |= 0x1;
- } else
- field |= ep_ring->cycle_state;
+ /* Set the correct cycle bit (inverted for first TRB). */
+ trb_type_flags ^= ep_ring->cycle_state;
- /* Chain all the TRBs together; clear the chain bit in the last
- * TRB to indicate it's the last TRB in the chain.
- */
- if (trb_buff_len != len_left) {
- if (trb_buff_len == 0)
- goto next_frag;
- field |= TRB_CHAIN;
- } else {
+ /* Check for last fragment... */
+ if (trb_buff_len == len_left) {
/* FIXME - add check for ZERO_PACKET flag before this */
urb_priv = urb->hcpriv;
urb_priv->td[0]->last_trb = ep_ring->enqueue;
- field |= TRB_IOC;
+ /* Request interrupt and clear chain */
+ trb_type_flags ^= TRB_IOC | TRB_CHAIN;
+ } else {
+ if (trb_buff_len == 0)
+ goto next_frag;
}
- /* Only set interrupt on short packet for IN endpoints */
- if (usb_urb_dir_in(urb))
- field |= TRB_ISP;
-
/* Set the TRB length, TD size, and interrupter fields. */
if (xhci->hci_version < 0x100) {
remainder = xhci_td_remainder(len_left);
@@ -3375,12 +3370,15 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
lower_32_bits(addr),
upper_32_bits(addr),
length_field,
- field | TRB_TYPE(TRB_NORMAL));
+ trb_type_flags);
/* If we didn't set the chain bit, we must have finished */
- if (!(field & TRB_CHAIN))
+ if (!(trb_type_flags & TRB_CHAIN))
break;
+ /* We want the current cycle in subsequent TRB */
+ trb_type_flags &= ~TRB_CYCLE;
+
running_total += trb_buff_len;
len_left -= trb_buff_len;
--
1.8.1.2
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