diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 50 |
1 files changed, 44 insertions, 6 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 9d3f9dd1ad2..f72149b666b 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; } /* |