in host/xhci-ring.c [2588:2960]
static int handle_tx_event(struct xhci_hcd *xhci,
struct xhci_transfer_event *event)
{
struct xhci_virt_ep *ep;
struct xhci_ring *ep_ring;
unsigned int slot_id;
int ep_index;
struct xhci_td *td = NULL;
dma_addr_t ep_trb_dma;
struct xhci_segment *ep_seg;
union xhci_trb *ep_trb;
int status = -EINPROGRESS;
struct xhci_ep_ctx *ep_ctx;
struct list_head *tmp;
u32 trb_comp_code;
int td_num = 0;
bool handling_skipped_tds = false;
slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
ep_trb_dma = le64_to_cpu(event->buffer);
ep = xhci_get_virt_ep(xhci, slot_id, ep_index);
if (!ep) {
xhci_err(xhci, "ERROR Invalid Transfer event\n");
goto err_out;
}
ep_ring = xhci_dma_to_transfer_ring(ep, ep_trb_dma);
ep_ctx = xhci_get_ep_ctx(xhci, ep->vdev->out_ctx, ep_index);
if (GET_EP_CTX_STATE(ep_ctx) == EP_STATE_DISABLED) {
xhci_err(xhci,
"ERROR Transfer event for disabled endpoint slot %u ep %u\n",
slot_id, ep_index);
goto err_out;
}
/* Some transfer events don't always point to a trb, see xhci 4.17.4 */
if (!ep_ring) {
switch (trb_comp_code) {
case COMP_STALL_ERROR:
case COMP_USB_TRANSACTION_ERROR:
case COMP_INVALID_STREAM_TYPE_ERROR:
case COMP_INVALID_STREAM_ID_ERROR:
xhci_handle_halted_endpoint(xhci, ep, 0, NULL,
EP_SOFT_RESET);
goto cleanup;
case COMP_RING_UNDERRUN:
case COMP_RING_OVERRUN:
case COMP_STOPPED_LENGTH_INVALID:
goto cleanup;
default:
xhci_err(xhci, "ERROR Transfer event for unknown stream ring slot %u ep %u\n",
slot_id, ep_index);
goto err_out;
}
}
/* Count current td numbers if ep->skip is set */
if (ep->skip) {
list_for_each(tmp, &ep_ring->td_list)
td_num++;
}
/* Look for common error cases */
switch (trb_comp_code) {
/* Skip codes that require special handling depending on
* transfer type
*/
case COMP_SUCCESS:
if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) == 0)
break;
if (xhci->quirks & XHCI_TRUST_TX_LENGTH ||
ep_ring->last_td_was_short)
trb_comp_code = COMP_SHORT_PACKET;
else
xhci_warn_ratelimited(xhci,
"WARN Successful completion on short TX for slot %u ep %u: needs XHCI_TRUST_TX_LENGTH quirk?\n",
slot_id, ep_index);
break;
case COMP_SHORT_PACKET:
break;
/* Completion codes for endpoint stopped state */
case COMP_STOPPED:
xhci_dbg(xhci, "Stopped on Transfer TRB for slot %u ep %u\n",
slot_id, ep_index);
break;
case COMP_STOPPED_LENGTH_INVALID:
xhci_dbg(xhci,
"Stopped on No-op or Link TRB for slot %u ep %u\n",
slot_id, ep_index);
break;
case COMP_STOPPED_SHORT_PACKET:
xhci_dbg(xhci,
"Stopped with short packet transfer detected for slot %u ep %u\n",
slot_id, ep_index);
break;
/* Completion codes for endpoint halted state */
case COMP_STALL_ERROR:
xhci_dbg(xhci, "Stalled endpoint for slot %u ep %u\n", slot_id,
ep_index);
status = -EPIPE;
break;
case COMP_SPLIT_TRANSACTION_ERROR:
xhci_dbg(xhci, "Split transaction error for slot %u ep %u\n",
slot_id, ep_index);
status = -EPROTO;
break;
case COMP_USB_TRANSACTION_ERROR:
xhci_dbg(xhci, "Transfer error for slot %u ep %u on endpoint\n",
slot_id, ep_index);
status = -EPROTO;
break;
case COMP_BABBLE_DETECTED_ERROR:
xhci_dbg(xhci, "Babble error for slot %u ep %u on endpoint\n",
slot_id, ep_index);
status = -EOVERFLOW;
break;
/* Completion codes for endpoint error state */
case COMP_TRB_ERROR:
xhci_warn(xhci,
"WARN: TRB error for slot %u ep %u on endpoint\n",
slot_id, ep_index);
status = -EILSEQ;
break;
/* completion codes not indicating endpoint state change */
case COMP_DATA_BUFFER_ERROR:
xhci_warn(xhci,
"WARN: HC couldn't access mem fast enough for slot %u ep %u\n",
slot_id, ep_index);
status = -ENOSR;
break;
case COMP_BANDWIDTH_OVERRUN_ERROR:
xhci_warn(xhci,
"WARN: bandwidth overrun event for slot %u ep %u on endpoint\n",
slot_id, ep_index);
break;
case COMP_ISOCH_BUFFER_OVERRUN:
xhci_warn(xhci,
"WARN: buffer overrun event for slot %u ep %u on endpoint",
slot_id, ep_index);
break;
case COMP_RING_UNDERRUN:
/*
* When the Isoch ring is empty, the xHC will generate
* a Ring Overrun Event for IN Isoch endpoint or Ring
* Underrun Event for OUT Isoch endpoint.
*/
xhci_dbg(xhci, "underrun event on endpoint\n");
if (!list_empty(&ep_ring->td_list))
xhci_dbg(xhci, "Underrun Event for slot %d ep %d "
"still with TDs queued?\n",
TRB_TO_SLOT_ID(le32_to_cpu(event->flags)),
ep_index);
goto cleanup;
case COMP_RING_OVERRUN:
xhci_dbg(xhci, "overrun event on endpoint\n");
if (!list_empty(&ep_ring->td_list))
xhci_dbg(xhci, "Overrun Event for slot %d ep %d "
"still with TDs queued?\n",
TRB_TO_SLOT_ID(le32_to_cpu(event->flags)),
ep_index);
goto cleanup;
case COMP_MISSED_SERVICE_ERROR:
/*
* When encounter missed service error, one or more isoc tds
* may be missed by xHC.
* Set skip flag of the ep_ring; Complete the missed tds as
* short transfer when process the ep_ring next time.
*/
ep->skip = true;
xhci_dbg(xhci,
"Miss service interval error for slot %u ep %u, set skip flag\n",
slot_id, ep_index);
goto cleanup;
case COMP_NO_PING_RESPONSE_ERROR:
ep->skip = true;
xhci_dbg(xhci,
"No Ping response error for slot %u ep %u, Skip one Isoc TD\n",
slot_id, ep_index);
goto cleanup;
case COMP_INCOMPATIBLE_DEVICE_ERROR:
/* needs disable slot command to recover */
xhci_warn(xhci,
"WARN: detect an incompatible device for slot %u ep %u",
slot_id, ep_index);
status = -EPROTO;
break;
default:
if (xhci_is_vendor_info_code(xhci, trb_comp_code)) {
status = 0;
break;
}
xhci_warn(xhci,
"ERROR Unknown event condition %u for slot %u ep %u , HC probably busted\n",
trb_comp_code, slot_id, ep_index);
goto cleanup;
}
do {
/* This TRB should be in the TD at the head of this ring's
* TD list.
*/
if (list_empty(&ep_ring->td_list)) {
/*
* Don't print wanings if it's due to a stopped endpoint
* generating an extra completion event if the device
* was suspended. Or, a event for the last TRB of a
* short TD we already got a short event for.
* The short TD is already removed from the TD list.
*/
if (!(trb_comp_code == COMP_STOPPED ||
trb_comp_code == COMP_STOPPED_LENGTH_INVALID ||
ep_ring->last_td_was_short)) {
xhci_warn(xhci, "WARN Event TRB for slot %d ep %d with no TDs queued?\n",
TRB_TO_SLOT_ID(le32_to_cpu(event->flags)),
ep_index);
}
if (ep->skip) {
ep->skip = false;
xhci_dbg(xhci, "td_list is empty while skip flag set. Clear skip flag for slot %u ep %u.\n",
slot_id, ep_index);
}
if (trb_comp_code == COMP_STALL_ERROR ||
xhci_requires_manual_halt_cleanup(xhci, ep_ctx,
trb_comp_code)) {
xhci_handle_halted_endpoint(xhci, ep,
ep_ring->stream_id,
NULL,
EP_HARD_RESET);
}
goto cleanup;
}
/* We've skipped all the TDs on the ep ring when ep->skip set */
if (ep->skip && td_num == 0) {
ep->skip = false;
xhci_dbg(xhci, "All tds on the ep_ring skipped. Clear skip flag for slot %u ep %u.\n",
slot_id, ep_index);
goto cleanup;
}
td = list_first_entry(&ep_ring->td_list, struct xhci_td,
td_list);
if (ep->skip)
td_num--;
/* Is this a TRB in the currently executing TD? */
ep_seg = trb_in_td(xhci, ep_ring->deq_seg, ep_ring->dequeue,
td->last_trb, ep_trb_dma, false);
/*
* Skip the Force Stopped Event. The event_trb(event_dma) of FSE
* is not in the current TD pointed by ep_ring->dequeue because
* that the hardware dequeue pointer still at the previous TRB
* of the current TD. The previous TRB maybe a Link TD or the
* last TRB of the previous TD. The command completion handle
* will take care the rest.
*/
if (!ep_seg && (trb_comp_code == COMP_STOPPED ||
trb_comp_code == COMP_STOPPED_LENGTH_INVALID)) {
goto cleanup;
}
if (!ep_seg) {
if (!ep->skip ||
!usb_endpoint_xfer_isoc(&td->urb->ep->desc)) {
/* Some host controllers give a spurious
* successful event after a short transfer.
* Ignore it.
*/
if ((xhci->quirks & XHCI_SPURIOUS_SUCCESS) &&
ep_ring->last_td_was_short) {
ep_ring->last_td_was_short = false;
goto cleanup;
}
/* HC is busted, give up! */
xhci_err(xhci,
"ERROR Transfer event TRB DMA ptr not "
"part of current TD ep_index %d "
"comp_code %u\n", ep_index,
trb_comp_code);
trb_in_td(xhci, ep_ring->deq_seg,
ep_ring->dequeue, td->last_trb,
ep_trb_dma, true);
return -ESHUTDOWN;
}
skip_isoc_td(xhci, td, ep, status);
goto cleanup;
}
if (trb_comp_code == COMP_SHORT_PACKET)
ep_ring->last_td_was_short = true;
else
ep_ring->last_td_was_short = false;
if (ep->skip) {
xhci_dbg(xhci,
"Found td. Clear skip flag for slot %u ep %u.\n",
slot_id, ep_index);
ep->skip = false;
}
ep_trb = &ep_seg->trbs[(ep_trb_dma - ep_seg->dma) /
sizeof(*ep_trb)];
trace_xhci_handle_transfer(ep_ring,
(struct xhci_generic_trb *) ep_trb);
/*
* No-op TRB could trigger interrupts in a case where
* a URB was killed and a STALL_ERROR happens right
* after the endpoint ring stopped. Reset the halted
* endpoint. Otherwise, the endpoint remains stalled
* indefinitely.
*/
if (trb_is_noop(ep_trb)) {
if (trb_comp_code == COMP_STALL_ERROR ||
xhci_requires_manual_halt_cleanup(xhci, ep_ctx,
trb_comp_code))
xhci_handle_halted_endpoint(xhci, ep,
ep_ring->stream_id,
td, EP_HARD_RESET);
goto cleanup;
}
td->status = status;
/* update the urb's actual_length and give back to the core */
if (usb_endpoint_xfer_control(&td->urb->ep->desc))
process_ctrl_td(xhci, ep, ep_ring, td, ep_trb, event);
else if (usb_endpoint_xfer_isoc(&td->urb->ep->desc))
process_isoc_td(xhci, ep, ep_ring, td, ep_trb, event);
else
process_bulk_intr_td(xhci, ep, ep_ring, td, ep_trb, event);
cleanup:
handling_skipped_tds = ep->skip &&
trb_comp_code != COMP_MISSED_SERVICE_ERROR &&
trb_comp_code != COMP_NO_PING_RESPONSE_ERROR;
/*
* Do not update event ring dequeue pointer if we're in a loop
* processing missed tds.
*/
if (!handling_skipped_tds)
inc_deq(xhci, xhci->event_ring);
/*
* If ep->skip is set, it means there are missed tds on the
* endpoint ring need to take care of.
* Process them as short transfer until reach the td pointed by
* the event.
*/
} while (handling_skipped_tds);
return 0;
err_out:
xhci_err(xhci, "@%016llx %08x %08x %08x %08x\n",
(unsigned long long) xhci_trb_virt_to_dma(
xhci->event_ring->deq_seg,
xhci->event_ring->dequeue),
lower_32_bits(le64_to_cpu(event->buffer)),
upper_32_bits(le64_to_cpu(event->buffer)),
le32_to_cpu(event->transfer_len),
le32_to_cpu(event->flags));
return -ENODEV;
}