USB: xHCI: Fix another bug in link TRB activation change.

[net-next-2.6.git] / drivers / usb / host / xhci-ring.c

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9012098add6baefada9cd6155d57be8f9708afd7..bfc99a93945506bc745d830cf0bd4efbfcc4a92e 100644 (file)
--- 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),
@@ -2350,18 +2380,21 @@ static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
                u32 field3, u32 field4, bool command_must_succeed)
 {
        int reserved_trbs = xhci->cmd_ring_reserved_trbs;
+       int ret;
+
        if (!command_must_succeed)
                reserved_trbs++;
 
-       if (!room_on_ring(xhci, xhci->cmd_ring, reserved_trbs)) {
-               if (!in_interrupt())
-                       xhci_err(xhci, "ERR: No room for command on command ring\n");
+       ret = prepare_ring(xhci, xhci->cmd_ring, EP_STATE_RUNNING,
+                       reserved_trbs, GFP_ATOMIC);
+       if (ret < 0) {
+               xhci_err(xhci, "ERR: No room for command on command ring\n");
                if (command_must_succeed)
                        xhci_err(xhci, "ERR: Reserved TRB counting for "
                                        "unfailable commands failed.\n");
-               return -ENOMEM;
+               return ret;
        }
-       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;
 }