The 'cleanup' code at the bottom of xhci_queue_isoc_tx() can never be executed.
For 'i != 0' on an ISOC ring prepare_transfer can only fail if the endpoint
ring cannot be determined, but it was found only moments earlier (it could
be passed as a parameter).
The 'running_total' check is just checking that the code is correct
and can just be deleted now the code is working.
Remove the 'flip_cycle' parameter to td_to_noop() since it is no longer
ever set.
Signed-off-by: David Laight <david.lai...@aculab.com>
---
drivers/usb/host/xhci-ring.c | 56 ++++----------------------------------------
1 file changed, 5 insertions(+), 51 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 62049e5..ae5d32c 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -617,12 +617,8 @@ 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, bool flip_cycle)
+ struct xhci_td *cur_td)
{
struct xhci_segment *cur_seg;
union xhci_trb *cur_trb;
@@ -635,12 +631,6 @@ 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_trace(xhci, trace_xhci_dbg_cancel_urb,
"Cancel (unchain) link TRB");
xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
@@ -656,11 +646,6 @@ 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_trace(xhci, trace_xhci_dbg_cancel_urb,
@@ -834,7 +819,7 @@ static void xhci_handle_cmd_stop_ep(struct xhci_hcd *xhci,
int slot_id,
cur_td->urb->stream_id,
cur_td, &deq_state);
else
- td_to_noop(xhci, ep_ring, cur_td, false);
+ td_to_noop(xhci, ep_ring, cur_td);
remove_finished_td:
/*
* The event handler won't see a completion for this TD anymore,
@@ -3834,11 +3819,9 @@ 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) {
- if (i == 0)
- return ret;
- goto cleanup;
- }
+ if (ret < 0)
+ /* This can only happen when for the first TD */
+ return ret;
td = urb_priv->td[i];
for (j = 0; j < trbs_per_td; j++) {
@@ -3922,13 +3905,6 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci,
gfp_t mem_flags,
addr += trb_buff_len;
td_remain_len -= trb_buff_len;
}
-
- /* Check TD length */
- if (running_total != td_len) {
- xhci_err(xhci, "ISOC TD length unmatch\n");
- ret = -EINVAL;
- goto cleanup;
- }
}
if (xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs == 0) {
@@ -3939,28 +3915,6 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci,
gfp_t mem_flags,
giveback_first_trb(xhci, slot_id, ep_index, ep_ring);
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;
- ep_ring->num_trbs_free = ep_ring->num_trbs_free_temp;
- usb_hcd_unlink_urb_from_ep(bus_to_hcd(urb->dev->bus), urb);
- return ret;
}
/*
--
1.8.1.2
--
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