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path: root/drivers/usb/host/xhci-ring.c
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Diffstat (limited to 'drivers/usb/host/xhci-ring.c')
-rw-r--r--drivers/usb/host/xhci-ring.c90
1 files changed, 63 insertions, 27 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 7113d16e2d3..54139a2f06c 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) "
@@ -719,14 +734,14 @@ 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,
* so remove it from the endpoint ring's TD list. Keep it in
* the cancelled TD list for URB completion later.
*/
- list_del(&cur_td->td_list);
+ list_del_init(&cur_td->td_list);
}
last_unlinked_td = cur_td;
xhci_stop_watchdog_timer_in_irq(xhci, ep);
@@ -754,7 +769,7 @@ remove_finished_td:
do {
cur_td = list_entry(ep->cancelled_td_list.next,
struct xhci_td, cancelled_td_list);
- list_del(&cur_td->cancelled_td_list);
+ list_del_init(&cur_td->cancelled_td_list);
/* Clean up the cancelled URB */
/* Doesn't matter what we pass for status, since the core will
@@ -862,9 +877,9 @@ void xhci_stop_endpoint_command_watchdog(unsigned long arg)
cur_td = list_first_entry(&ring->td_list,
struct xhci_td,
td_list);
- list_del(&cur_td->td_list);
+ list_del_init(&cur_td->td_list);
if (!list_empty(&cur_td->cancelled_td_list))
- list_del(&cur_td->cancelled_td_list);
+ list_del_init(&cur_td->cancelled_td_list);
xhci_giveback_urb_in_irq(xhci, cur_td,
-ESHUTDOWN, "killed");
}
@@ -873,7 +888,7 @@ void xhci_stop_endpoint_command_watchdog(unsigned long arg)
&temp_ep->cancelled_td_list,
struct xhci_td,
cancelled_td_list);
- list_del(&cur_td->cancelled_td_list);
+ list_del_init(&cur_td->cancelled_td_list);
xhci_giveback_urb_in_irq(xhci, cur_td,
-ESHUTDOWN, "killed");
}
@@ -1565,10 +1580,10 @@ td_cleanup:
else
*status = 0;
}
- list_del(&td->td_list);
+ list_del_init(&td->td_list);
/* Was this TD slated to be cancelled but completed anyway? */
if (!list_empty(&td->cancelled_td_list))
- list_del(&td->cancelled_td_list);
+ list_del_init(&td->cancelled_td_list);
urb_priv->td_cnt++;
/* Giveback the urb when all the tds are completed */
@@ -2500,11 +2515,8 @@ static int prepare_transfer(struct xhci_hcd *xhci,
if (td_index == 0) {
ret = usb_hcd_link_urb_to_ep(bus_to_hcd(urb->dev->bus), urb);
- if (unlikely(ret)) {
- xhci_urb_free_priv(xhci, urb_priv);
- urb->hcpriv = NULL;
+ if (unlikely(ret))
return ret;
- }
}
td->urb = urb;
@@ -2672,6 +2684,10 @@ static u32 xhci_v1_0_td_remainder(int running_total, int trb_buff_len,
{
int packets_transferred;
+ /* One TRB with a zero-length data packet. */
+ if (running_total == 0 && trb_buff_len == 0)
+ return 0;
+
/* All the TRB queueing functions don't count the current TRB in
* running_total.
*/
@@ -3113,20 +3129,15 @@ static int count_isoc_trbs_needed(struct xhci_hcd *xhci,
struct urb *urb, int i)
{
int num_trbs = 0;
- u64 addr, td_len, running_total;
+ u64 addr, td_len;
addr = (u64) (urb->transfer_dma + urb->iso_frame_desc[i].offset);
td_len = urb->iso_frame_desc[i].length;
- running_total = TRB_MAX_BUFF_SIZE - (addr & (TRB_MAX_BUFF_SIZE - 1));
- running_total &= TRB_MAX_BUFF_SIZE - 1;
- if (running_total != 0)
- num_trbs++;
-
- while (running_total < td_len) {
+ num_trbs = DIV_ROUND_UP(td_len + (addr & (TRB_MAX_BUFF_SIZE - 1)),
+ TRB_MAX_BUFF_SIZE);
+ if (num_trbs == 0)
num_trbs++;
- running_total += TRB_MAX_BUFF_SIZE;
- }
return num_trbs;
}
@@ -3226,6 +3237,7 @@ 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;
@@ -3237,9 +3249,11 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
addr = start_addr + urb->iso_frame_desc[i].offset;
td_len = urb->iso_frame_desc[i].length;
td_remain_len = td_len;
- /* FIXME: Ignoring zero-length packets, can those happen? */
total_packet_count = roundup(td_len,
le16_to_cpu(urb->ep->desc.wMaxPacketSize));
+ /* A zero-length transfer still involves at least one packet. */
+ if (total_packet_count == 0)
+ total_packet_count++;
burst_count = xhci_get_burst_count(xhci, urb->dev, urb,
total_packet_count);
residue = xhci_get_last_burst_packet_count(xhci,
@@ -3249,12 +3263,13 @@ 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);
@@ -3344,6 +3359,27 @@ 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_init(&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;
}
/*
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-11-04 01:21:59 +0000