Hi
On 02.07.2015 13:45, SAUROV KANTI SHYAM wrote:
> Some undefined values, mostly null are coming in event->buffer in my case for "stop,-invalid length” transfer event.
That doesn't sound good, what xhci vendor and version are you using?
Have you seen/tried this on other xhci hw as well?
What kernel version are you using? are there any custom xhci driver modification in it?
> However, in the portion of the code you suggested does not increment the dequeue pointer of transfer event ring, for trb_comp_code = COMP_STOP_INVAL.
> In handle_tx_event() cleanup: does not increment the dequeue pointer of transfer event ring.
> In xhci_handle_event():
> …
> case TRB_TYPE(TRB_TRANSFER):
> ret = handle_tx_event(xhci, &event->trans_event);
> if (ret < 0)
> xhci->error_bitmask |= 1 << 9;
> else
> update_ptrs = 0;
> …
> if (update_ptrs)
> /* Update SW event ring dequeue pointer */
> inc_deq(xhci, xhci->event_ring);
> …
> As update_ptrs=0, inc_deq(xhci, xhci->event_ring) won't run.
> Regards,
Event ring dequeue is increased either in handle_tx_event(), cleanup:
if (trb_comp_code == COMP_MISSED_INT || !ep->skip) {
inc_deq(xhci, xhci->event_ring);
Or then in xhci_handle_event() if handle_tx_event() returns error.
For example in handle_tx_event() if event->buffer is null, then
ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer)); is NULL
and the check immediately after would return with -ENODEV
-Mathias
P.S. The potion of code was not a suggestion, it was copypasted from the upstream xhci driver, and has
looked like that since 3.17 kernel
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