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-rw-r--r--drivers/usb/host/xhci-ring.c50
1 files changed, 44 insertions, 6 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9d3f9dd1ad28..f72149b666b1 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -514,8 +514,12 @@ void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
(unsigned long long) addr);
}
+/* flip_cycle means flip the cycle bit of all but the first and last TRB.
+ * (The last TRB actually points to the ring enqueue pointer, which is not part
+ * of this TD.) This is used to remove partially enqueued isoc TDs from a ring.
+ */
static void td_to_noop(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
- struct xhci_td *cur_td)
+ struct xhci_td *cur_td, bool flip_cycle)
{
struct xhci_segment *cur_seg;
union xhci_trb *cur_trb;
@@ -528,6 +532,12 @@ static void td_to_noop(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
* leave the pointers intact.
*/
cur_trb->generic.field[3] &= cpu_to_le32(~TRB_CHAIN);
+ /* Flip the cycle bit (link TRBs can't be the first
+ * or last TRB).
+ */
+ if (flip_cycle)
+ cur_trb->generic.field[3] ^=
+ cpu_to_le32(TRB_CYCLE);
xhci_dbg(xhci, "Cancel (unchain) link TRB\n");
xhci_dbg(xhci, "Address = %p (0x%llx dma); "
"in seg %p (0x%llx dma)\n",
@@ -541,6 +551,11 @@ static void td_to_noop(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
cur_trb->generic.field[2] = 0;
/* Preserve only the cycle bit of this TRB */
cur_trb->generic.field[3] &= cpu_to_le32(TRB_CYCLE);
+ /* Flip the cycle bit except on the first or last TRB */
+ if (flip_cycle && cur_trb != cur_td->first_trb &&
+ cur_trb != cur_td->last_trb)
+ cur_trb->generic.field[3] ^=
+ cpu_to_le32(TRB_CYCLE);
cur_trb->generic.field[3] |= cpu_to_le32(
TRB_TYPE(TRB_TR_NOOP));
xhci_dbg(xhci, "Cancel TRB %p (0x%llx dma) "
@@ -719,7 +734,7 @@ static void handle_stopped_endpoint(struct xhci_hcd *xhci,
cur_td->urb->stream_id,
cur_td, &deq_state);
else
- td_to_noop(xhci, ep_ring, cur_td);
+ td_to_noop(xhci, ep_ring, cur_td, false);
remove_finished_td:
/*
* The event handler won't see a completion for this TD anymore,
@@ -3223,6 +3238,7 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
start_trb = &ep_ring->enqueue->generic;
start_cycle = ep_ring->cycle_state;
+ urb_priv = urb->hcpriv;
/* Queue the first TRB, even if it's zero-length */
for (i = 0; i < num_tds; i++) {
unsigned int total_packet_count;
@@ -3246,12 +3262,13 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index,
urb->stream_id, trbs_per_td, urb, i, mem_flags);
- if (ret < 0)
- return ret;
+ if (ret < 0) {
+ if (i == 0)
+ return ret;
+ goto cleanup;
+ }
- urb_priv = urb->hcpriv;
td = urb_priv->td[i];
-
for (j = 0; j < trbs_per_td; j++) {
u32 remainder = 0;
field = TRB_TBC(burst_count) | TRB_TLBPC(residue);
@@ -3341,6 +3358,27 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
start_cycle, start_trb);
return 0;
+cleanup:
+ /* Clean up a partially enqueued isoc transfer. */
+
+ for (i--; i >= 0; i--)
+ list_del(&urb_priv->td[i]->td_list);
+
+ /* Use the first TD as a temporary variable to turn the TDs we've queued
+ * into No-ops with a software-owned cycle bit. That way the hardware
+ * won't accidentally start executing bogus TDs when we partially
+ * overwrite them. td->first_trb and td->start_seg are already set.
+ */
+ urb_priv->td[0]->last_trb = ep_ring->enqueue;
+ /* Every TRB except the first & last will have its cycle bit flipped. */
+ td_to_noop(xhci, ep_ring, urb_priv->td[0], true);
+
+ /* Reset the ring enqueue back to the first TRB and its cycle bit. */
+ ep_ring->enqueue = urb_priv->td[0]->first_trb;
+ ep_ring->enq_seg = urb_priv->td[0]->start_seg;
+ ep_ring->cycle_state = start_cycle;
+ usb_hcd_unlink_urb_from_ep(bus_to_hcd(urb->dev->bus), urb);
+ return ret;
}
/*
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