diff options
| -rw-r--r-- | drivers/usb/host/xhci-mem.c | 14 | ||||
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 64 |
2 files changed, 45 insertions, 33 deletions
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 2bf8121f4d36..c6f3ef2334a3 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -422,22 +422,14 @@ void xhci_free_endpoint_ring(struct xhci_hcd *xhci, * Allocate a new ring which has same segment numbers and link the two rings. */ int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_ring *ring, - unsigned int num_trbs, gfp_t flags) + unsigned int num_new_segs, gfp_t flags) { struct xhci_segment *first; struct xhci_segment *last; - unsigned int num_segs; - unsigned int num_segs_needed; int ret; - num_segs_needed = (num_trbs + (TRBS_PER_SEGMENT - 1) - 1) / - (TRBS_PER_SEGMENT - 1); - - /* Allocate number of segments we needed, or double the ring size */ - num_segs = max(ring->num_segs, num_segs_needed); - ret = xhci_alloc_segments_for_ring(xhci, &first, &last, - num_segs, ring->cycle_state, ring->type, + num_new_segs, ring->cycle_state, ring->type, ring->bounce_buf_len, flags); if (ret) return -ENOMEM; @@ -457,7 +449,7 @@ int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_ring *ring, return ret; } - xhci_link_rings(xhci, ring, first, last, num_segs); + xhci_link_rings(xhci, ring, first, last, num_new_segs); trace_xhci_ring_expansion(ring); xhci_dbg_trace(xhci, trace_xhci_dbg_ring_expansion, "ring expansion succeed, now has %d segments", diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 2bc82b3a2f98..2722dca6218e 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -299,22 +299,45 @@ static int xhci_num_trbs_to(struct xhci_segment *start_seg, union xhci_trb *star /* * Check to see if there's room to enqueue num_trbs on the ring and make sure * enqueue pointer will not advance into dequeue segment. See rules above. + * return number of new segments needed to ensure this. */ -static inline int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring, - unsigned int num_trbs) + +static unsigned int xhci_ring_expansion_needed(struct xhci_hcd *xhci, struct xhci_ring *ring, + unsigned int num_trbs) { - int num_trbs_in_deq_seg; + struct xhci_segment *seg; + int trbs_past_seg; + int enq_used; + int new_segs; + + enq_used = ring->enqueue - ring->enq_seg->trbs; - if (ring->num_trbs_free < num_trbs) + /* how many trbs will be queued past the enqueue segment? */ + trbs_past_seg = enq_used + num_trbs - (TRBS_PER_SEGMENT - 1); + + if (trbs_past_seg <= 0) return 0; - if (ring->type != TYPE_COMMAND && ring->type != TYPE_EVENT) { - num_trbs_in_deq_seg = ring->dequeue - ring->deq_seg->trbs; - if (ring->num_trbs_free < num_trbs + num_trbs_in_deq_seg) - return 0; + /* Empty ring special case, enqueue stuck on link trb while dequeue advanced */ + if (trb_is_link(ring->enqueue) && ring->enq_seg->next->trbs == ring->dequeue) + return 0; + + new_segs = 1 + (trbs_past_seg / (TRBS_PER_SEGMENT - 1)); + seg = ring->enq_seg; + + while (new_segs > 0) { + seg = seg->next; + if (seg == ring->deq_seg) { + xhci_dbg(xhci, "Ring expansion by %d segments needed\n", + new_segs); + xhci_dbg(xhci, "Adding %d trbs moves enq %d trbs into deq seg\n", + num_trbs, trbs_past_seg % TRBS_PER_SEGMENT); + return new_segs; + } + new_segs--; } - return 1; + return 0; } /* Ring the host controller doorbell after placing a command on the ring */ @@ -3165,13 +3188,13 @@ static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring, /* * Does various checks on the endpoint ring, and makes it ready to queue num_trbs. - * FIXME allocate segments if the ring is full. + * expand ring if it start to be full. */ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring, u32 ep_state, unsigned int num_trbs, gfp_t mem_flags) { - unsigned int num_trbs_needed; unsigned int link_trb_count = 0; + unsigned int new_segs = 0; /* Make sure the endpoint has been added to xHC schedule */ switch (ep_state) { @@ -3202,20 +3225,17 @@ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring, return -EINVAL; } - while (1) { - if (room_on_ring(xhci, ep_ring, num_trbs)) - break; - - if (ep_ring == xhci->cmd_ring) { - xhci_err(xhci, "Do not support expand command ring\n"); - return -ENOMEM; - } + if (ep_ring != xhci->cmd_ring) { + new_segs = xhci_ring_expansion_needed(xhci, ep_ring, num_trbs); + } else if (ep_ring->num_trbs_free <= num_trbs) { + xhci_err(xhci, "Do not support expand command ring\n"); + return -ENOMEM; + } + if (new_segs) { xhci_dbg_trace(xhci, trace_xhci_dbg_ring_expansion, "ERROR no room on ep ring, try ring expansion"); - num_trbs_needed = num_trbs - ep_ring->num_trbs_free; - if (xhci_ring_expansion(xhci, ep_ring, num_trbs_needed, - mem_flags)) { + if (xhci_ring_expansion(xhci, ep_ring, new_segs, mem_flags)) { xhci_err(xhci, "Ring expansion failed\n"); return -ENOMEM; } |