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xhci: Clean up cycle bit math used during stalls. 

Use XOR to invert the cycle bit, instead of a more complicated
calculation.  Eliminate a check for the link TRB type in find_trb_seg().
We know that there will always be a link TRB at the end of a segment, so
xhci_segment->trbs[TRBS_PER_SEGMENT - 1] will always have a link TRB type.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Sarah Sharp 2011-02-23 18:13:43 -08:00
parent 01a1fdb9a7
commit ba0a4d9aaa
1 changed files with 3 additions and 5 deletions
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8
drivers/usb/host/xhci-ring.c
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@ -380,10 +380,8 @@ static struct xhci_segment *find_trb_seg(
while (cur_seg->trbs > trb ||
&cur_seg->trbs[TRBS_PER_SEGMENT - 1] < trb) {
generic_trb = &cur_seg->trbs[TRBS_PER_SEGMENT - 1].generic;
if ((generic_trb->field[3] & TRB_TYPE_BITMASK) ==
TRB_TYPE(TRB_LINK) &&
(generic_trb->field[3] & LINK_TOGGLE))
*cycle_state = ~(*cycle_state) & 0x1;
if (generic_trb->field[3] & LINK_TOGGLE)
*cycle_state ^= 0x1;
cur_seg = cur_seg->next;
if (cur_seg == start_seg)
/* Looped over the entire list. Oops! */
@ -492,7 +490,7 @@ void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
trb = &state->new_deq_ptr->generic;
if ((trb->field[3] & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK) &&
(trb->field[3] & LINK_TOGGLE))
state->new_cycle_state = ~(state->new_cycle_state) & 0x1;
state->new_cycle_state ^= 0x1;
next_trb(xhci, ep_ring, &state->new_deq_seg, &state->new_deq_ptr);
/*