@@ -86,33 +86,31 @@ static void xhci_ring_segments_free(struct xhci_hcd *xhci, struct xhci_ring *rin
}
/*
- * Make the prev segment point to the next segment.
+ * Only for transfer and command rings where driver is the producer, not for
+ * event rings.
*
- * Change the last TRB in the prev segment to be a Link TRB which points to the
+ * Change the last TRB in the segment to be a Link TRB which points to the
* DMA address of the next segment. The caller needs to set any Link TRB
* related flags, such as End TRB, Toggle Cycle, and no snoop.
*/
-static void xhci_link_segments(struct xhci_segment *prev,
- struct xhci_segment *next,
- enum xhci_ring_type type, bool chain_links)
+static void xhci_set_link_trb(struct xhci_segment *seg, bool chain_links)
{
+ union xhci_trb *trb;
u32 val;
- if (!prev || !next)
+ if (!seg || !seg->next)
return;
- prev->next = next;
- if (type != TYPE_EVENT) {
- prev->trbs[TRBS_PER_SEGMENT-1].link.segment_ptr =
- cpu_to_le64(next->dma);
- /* Set the last TRB in the segment to have a TRB type ID of Link TRB */
- val = le32_to_cpu(prev->trbs[TRBS_PER_SEGMENT-1].link.control);
- val &= ~TRB_TYPE_BITMASK;
- val |= TRB_TYPE(TRB_LINK);
- if (chain_links)
- val |= TRB_CHAIN;
- prev->trbs[TRBS_PER_SEGMENT-1].link.control = cpu_to_le32(val);
- }
+ trb = &seg->trbs[TRBS_PER_SEGMENT - 1];
+
+ /* Set the last TRB in the segment to have a TRB type ID of Link TRB */
+ val = le32_to_cpu(trb->link.control);
+ val &= ~TRB_TYPE_BITMASK;
+ val |= TRB_TYPE(TRB_LINK);
+ if (chain_links)
+ val |= TRB_CHAIN;
+ trb->link.control = cpu_to_le32(val);
+ trb->link.segment_ptr = cpu_to_le64(seg->next->dma);
}
/*
@@ -127,8 +125,6 @@ static void xhci_link_rings(struct xhci_hcd *xhci, struct xhci_ring *src, struct
if (!src || !dst)
return;
- chain_links = xhci_link_chain_quirk(xhci, dst->type);
-
/* If the cycle state is 0, set the cycle bit to 1 for all the TRBs */
if (dst->cycle_state == 0) {
xhci_for_each_ring_seg(src->first_seg, seg) {
@@ -137,8 +133,13 @@ static void xhci_link_rings(struct xhci_hcd *xhci, struct xhci_ring *src, struct
}
}
- xhci_link_segments(src->last_seg, dst->enq_seg->next, dst->type, chain_links);
- xhci_link_segments(dst->enq_seg, src->first_seg, dst->type, chain_links);
+ src->last_seg->next = dst->enq_seg->next;
+ dst->enq_seg->next = src->first_seg;
+ if (dst->type != TYPE_EVENT) {
+ chain_links = xhci_link_chain_quirk(xhci, dst->type);
+ xhci_set_link_trb(dst->enq_seg, chain_links);
+ xhci_set_link_trb(src->last_seg, chain_links);
+ }
dst->num_segs += src->num_segs;
if (dst->enq_seg == dst->last_seg) {
@@ -331,13 +332,18 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci, struct xhci_ring
if (!next)
goto free_segments;
- xhci_link_segments(prev, next, ring->type, chain_links);
+ prev->next = next;
+ if (ring->type != TYPE_EVENT)
+ xhci_set_link_trb(prev, chain_links);
prev = next;
num++;
}
- xhci_link_segments(prev, ring->first_seg, ring->type, chain_links);
ring->last_seg = prev;
+ ring->last_seg->next = ring->first_seg;
+ if (ring->type != TYPE_EVENT)
+ xhci_set_link_trb(prev, chain_links);
+
return 0;
free_segments: