diff options
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 62 |
1 files changed, 46 insertions, 16 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 9012098add6b..94e6934edb09 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -182,8 +182,12 @@ static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer * set, but other sections talk about dealing with the chain bit set. This was * fixed in the 0.96 specification errata, but we have to assume that all 0.95 * xHCI hardware can't handle the chain bit being cleared on a link TRB. + * + * @more_trbs_coming: Will you enqueue more TRBs before calling + * prepare_transfer()? */ -static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer) +static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, + bool consumer, bool more_trbs_coming) { u32 chain; union xhci_trb *next; @@ -199,15 +203,28 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer while (last_trb(xhci, ring, ring->enq_seg, next)) { if (!consumer) { if (ring != xhci->event_ring) { - if (chain) { - next->link.control |= TRB_CHAIN; - - /* Give this link TRB to the hardware */ - wmb(); - next->link.control ^= TRB_CYCLE; - } else { + /* + * 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, + * carry over the chain bit of the previous TRB + * (which may mean the chain bit is cleared). + */ + if (!xhci_link_trb_quirk(xhci)) { + next->link.control &= ~TRB_CHAIN; + next->link.control |= chain; } + /* Give this link TRB to the hardware */ + wmb(); + next->link.control ^= TRB_CYCLE; } /* Toggle the cycle bit after the last ring segment. */ if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) { @@ -1707,9 +1724,12 @@ void xhci_handle_event(struct xhci_hcd *xhci) /* * Generic function for queueing a TRB on a ring. * The caller must have checked to make sure there's room on the ring. + * + * @more_trbs_coming: Will you enqueue more TRBs before calling + * prepare_transfer()? */ static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring, - bool consumer, + bool consumer, bool more_trbs_coming, u32 field1, u32 field2, u32 field3, u32 field4) { struct xhci_generic_trb *trb; @@ -1719,7 +1739,7 @@ static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring, trb->field[1] = field2; trb->field[2] = field3; trb->field[3] = field4; - inc_enq(xhci, ring, consumer); + inc_enq(xhci, ring, consumer, more_trbs_coming); } /* @@ -1988,6 +2008,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, int trb_buff_len, this_sg_len, running_total; bool first_trb; u64 addr; + bool more_trbs_coming; struct xhci_generic_trb *start_trb; int start_cycle; @@ -2073,7 +2094,11 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, length_field = TRB_LEN(trb_buff_len) | remainder | TRB_INTR_TARGET(0); - queue_trb(xhci, ep_ring, false, + if (num_trbs > 1) + more_trbs_coming = true; + else + more_trbs_coming = false; + queue_trb(xhci, ep_ring, false, more_trbs_coming, lower_32_bits(addr), upper_32_bits(addr), length_field, @@ -2124,6 +2149,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, int num_trbs; struct xhci_generic_trb *start_trb; bool first_trb; + bool more_trbs_coming; int start_cycle; u32 field, length_field; @@ -2212,7 +2238,11 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, length_field = TRB_LEN(trb_buff_len) | remainder | TRB_INTR_TARGET(0); - queue_trb(xhci, ep_ring, false, + if (num_trbs > 1) + more_trbs_coming = true; + else + more_trbs_coming = false; + queue_trb(xhci, ep_ring, false, more_trbs_coming, lower_32_bits(addr), upper_32_bits(addr), length_field, @@ -2291,7 +2321,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags, /* Queue setup TRB - see section 6.4.1.2.1 */ /* FIXME better way to translate setup_packet into two u32 fields? */ setup = (struct usb_ctrlrequest *) urb->setup_packet; - queue_trb(xhci, ep_ring, false, + queue_trb(xhci, ep_ring, false, true, /* FIXME endianness is probably going to bite my ass here. */ setup->bRequestType | setup->bRequest << 8 | setup->wValue << 16, setup->wIndex | setup->wLength << 16, @@ -2307,7 +2337,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags, if (urb->transfer_buffer_length > 0) { if (setup->bRequestType & USB_DIR_IN) field |= TRB_DIR_IN; - queue_trb(xhci, ep_ring, false, + queue_trb(xhci, ep_ring, false, true, lower_32_bits(urb->transfer_dma), upper_32_bits(urb->transfer_dma), length_field, @@ -2324,7 +2354,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags, field = 0; else field = TRB_DIR_IN; - queue_trb(xhci, ep_ring, false, + queue_trb(xhci, ep_ring, false, false, 0, 0, TRB_INTR_TARGET(0), @@ -2361,7 +2391,7 @@ static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2, "unfailable commands failed.\n"); return -ENOMEM; } - queue_trb(xhci, xhci->cmd_ring, false, field1, field2, field3, + queue_trb(xhci, xhci->cmd_ring, false, false, field1, field2, field3, field4 | xhci->cmd_ring->cycle_state); return 0; } |
