diff options
| author | Andiry Xu <andiry.xu@amd.com> | 2012-03-05 17:49:34 +0800 |
|---|---|---|
| committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2012-03-13 09:29:55 -0700 |
| commit | b008df60c6369ba0290fa7daa177375407a12e07 (patch) | |
| tree | 05a59c4a4d8d624b18ad0844949841f36b241c17 /drivers/usb/host/xhci-mem.c | |
| parent | 3fe4fe083d3355537565b2b0a678807513dfa013 (diff) | |
xHCI: count free TRBs on transfer ring
In the past, the room_on_ring() check was implemented by walking all over
the ring, which is wasteful and complicated.
Count the number of free TRBs instead. The free TRBs number should be
updated when enqueue/dequeue pointer is updated, or upon the completion
of a set dequeue pointer command.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Paul Zimmerman <Paul.Zimmerman@synopsys.com>
Diffstat (limited to 'drivers/usb/host/xhci-mem.c')
| -rw-r--r-- | drivers/usb/host/xhci-mem.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index bdea4de867b..212012c97df 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -135,6 +135,12 @@ static void xhci_initialize_ring_info(struct xhci_ring *ring) /* Not necessary for new rings, but needed for re-initialized rings */ ring->enq_updates = 0; ring->deq_updates = 0; + + /* + * Each segment has a link TRB, and leave an extra TRB for SW + * accounting purpose + */ + ring->num_trbs_free = ring->num_segs * (TRBS_PER_SEGMENT - 1) - 1; } /** |