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xhci: clean up event ring checks from inc_enq()

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Remove the event ring related checks in inc_enq()

Host hardware is the producer of events on the event ring,
driver will not queue anything, or call inc_enq() for the
event ring.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman 2016-06-21 10:58:03 +03:00 committed by Greg Kroah-Hartman
parent f9c589e142
commit 2251198bef
1 changed files with 28 additions and 36 deletions
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64
drivers/usb/host/xhci-ring.c
View file

@ -199,50 +199,42 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring,
chain = le32_to_cpu(ring->enqueue->generic.field[3]) & TRB_CHAIN;
/* If this is not event ring, there is one less usable TRB */
if (ring->type != TYPE_EVENT &&
!last_trb(xhci, ring, ring->enq_seg, ring->enqueue))
if (!last_trb(xhci, ring, ring->enq_seg, ring->enqueue))
ring->num_trbs_free--;
next = ++(ring->enqueue);
ring->enq_updates++;
/* Update the dequeue pointer further if that was a link TRB or we're at
* the end of an event ring segment (which doesn't have link TRBS)
*/
/* Update the dequeue pointer further if that was a link TRB */
while (last_trb(xhci, ring, ring->enq_seg, next)) {
if (ring->type != TYPE_EVENT) {
/*
* If the caller doesn't plan on enqueueing more
* TDs before ringing the doorbell, then we
* don't want to give the link TRB to the
* hardware just yet. We'll give the link TRB
* back in prepare_ring() just before we enqueue
* the TD at the top of the ring.
*/
if (!chain && !more_trbs_coming)
break;
/* If we're not dealing with 0.95 hardware or
* isoc rings on AMD 0.96 host,
* carry over the chain bit of the previous TRB
* (which may mean the chain bit is cleared).
*/
if (!(ring->type == TYPE_ISOC &&
(xhci->quirks & XHCI_AMD_0x96_HOST))
&& !xhci_link_trb_quirk(xhci)) {
next->link.control &=
cpu_to_le32(~TRB_CHAIN);
next->link.control |=
cpu_to_le32(chain);
}
/* Give this link TRB to the hardware */
wmb();
next->link.control ^= cpu_to_le32(TRB_CYCLE);
/*
* If the caller doesn't plan on enqueueing more TDs before
* ringing the doorbell, then we don't want to give the link TRB
* to the hardware just yet. We'll give the link TRB back in
* prepare_ring() just before we enqueue the TD at the top of
* the ring.
*/
if (!chain && !more_trbs_coming)
break;
/* Toggle the cycle bit after the last ring segment. */
if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
ring->cycle_state ^= 1;
}
/* If we're not dealing with 0.95 hardware or isoc rings on
* AMD 0.96 host, carry over the chain bit of the previous TRB
* (which may mean the chain bit is cleared).
*/
if (!(ring->type == TYPE_ISOC &&
(xhci->quirks & XHCI_AMD_0x96_HOST)) &&
!xhci_link_trb_quirk(xhci)) {
next->link.control &= cpu_to_le32(~TRB_CHAIN);
next->link.control |= cpu_to_le32(chain);
}
/* Give this link TRB to the hardware */
wmb();
next->link.control ^= cpu_to_le32(TRB_CYCLE);
/* Toggle the cycle bit after the last ring segment. */
if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next))
ring->cycle_state ^= 1;
ring->enq_seg = ring->enq_seg->next;
ring->enqueue = ring->enq_seg->trbs;
next = ring->enqueue;