On Tue, Jul 20, 2010 at 04:49:25PM +0800, Andiry Xu wrote:
> >From 02b3e01af9fef97d113f30de96c07f6a4c24a895 Mon Sep 17 00:00:00 2001
> From: Andiry Xu <andiry.xu@xxxxxxx>
> Date: Thu, 15 Jul 2010 16:14:09 +0800
> Subject: [PATCH 06/10] xHCI: Missed Service Error Event process
>
> This patch adds mechanism to process Missed Service Error Event.
> Sometimes the xHC is unable to process the isoc TDs in time, it will
> generate Missed Service Error Event. In this case some TDs on the ring are
> not processed and missed. When encounter a Missed Servce Error Event, set
> the skip flag of the ep, and process the missed TDs until reach the next
> processed TD, then clear the skip flag.
>
> Signed-off-by: Andiry Xu <andiry.xu@xxxxxxx>
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/host/xhci-mem.c | 1 +
> drivers/usb/host/xhci-ring.c | 158 ++++++++++++++++++++++++++++-------------
> drivers/usb/host/xhci.h | 8 ++
> 3 files changed, 117 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
> index 8cc824b..5763dd3 100644
> --- a/drivers/usb/host/xhci-mem.c
> +++ b/drivers/usb/host/xhci-mem.c
> @@ -1123,6 +1123,7 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
> virt_dev->num_rings_cached--;
> xhci_reinit_cached_ring(xhci, virt_dev->eps[ep_index].new_ring);
> }
> + virt_dev->eps[ep_index].skip = false;
> ep_ring = virt_dev->eps[ep_index].new_ring;
> ep_ctx->deq = ep_ring->first_seg->dma | ep_ring->cycle_state;
>
> diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
> index 5bb12fe..4c35010 100644
> --- a/drivers/usb/host/xhci-ring.c
> +++ b/drivers/usb/host/xhci-ring.c
> @@ -1675,6 +1675,16 @@ static int handle_tx_event(struct xhci_hcd *xhci,
> "still with TDs queued?\n",
> TRB_TO_SLOT_ID(event->flags), ep_index);
> goto cleanup;
> + case COMP_MISSED_INT:
> + /*
> + * 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, set skip flag\n");
> + goto cleanup;
> default:
> if (xhci_is_vendor_info_code(xhci, trb_comp_code)) {
> status = 0;
> @@ -1685,60 +1695,108 @@ static int handle_tx_event(struct xhci_hcd *xhci,
> goto cleanup;
> }
>
> - /* This TRB should be in the TD at the head of this ring's TD list */
> - if (list_empty(&ep_ring->td_list)) {
> - xhci_warn(xhci, "WARN Event TRB for slot %d ep %d with no TDs queued?\n",
> - TRB_TO_SLOT_ID(event->flags), ep_index);
> - xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
> - (unsigned int) (event->flags & TRB_TYPE_BITMASK)>>10);
> - xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
> - goto cleanup;
> - }
> - td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
> -
> - /* Is this a TRB in the currently executing TD? */
> - event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
> - td->last_trb, event_dma);
> - if (!event_seg) {
> - /* HC is busted, give up! */
> - xhci_err(xhci, "ERROR Transfer event TRB DMA ptr not part of current TD\n");
> - return -ESHUTDOWN;
> - }
> - event_trb = &event_seg->trbs[(event_dma - event_seg->dma) / sizeof(*event_trb)];
> + do {
> + /* This TRB should be in the TD at the head of this ring's
> + * TD list.
> + */
> + if (list_empty(&ep_ring->td_list)) {
> + xhci_warn(xhci, "WARN Event TRB for slot %d ep %d "
> + "with no TDs queued?\n",
> + TRB_TO_SLOT_ID(event->flags), ep_index);
> + xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
> + (unsigned int) (event->flags & TRB_TYPE_BITMASK)>>10);
> + xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
> + if (ep->skip) {
> + ep->skip = false;
> + xhci_dbg(xhci, "td_list is empty while skip "
> + "flag set. Clear skip flag.\n");
> + }
> + ret = 0;
> + goto cleanup;
> + }
>
> - /* Now update the urb's actual_length and give back to the core */
> - /* Was this a control transfer? */
> - if (usb_endpoint_xfer_control(&td->urb->ep->desc))
> - ret = process_ctrl_td(xhci, td, event_trb, event, ep,
> - &status);
> - else
> - ret = process_bulk_intr_td(xhci, td, event_trb, event, ep,
> - &status);
> + td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
> + /* Is this a TRB in the currently executing TD? */
> + event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
> + td->last_trb, event_dma);
> + if (event_seg && ep->skip) {
> + xhci_dbg(xhci, "Found td. Clear skip flag.\n");
> + ep->skip = false;
> + }
> + if (!event_seg &&
> + (!ep->skip || !usb_endpoint_xfer_isoc(&td->urb->ep->desc))) {
> + /* HC is busted, give up! */
> + xhci_err(xhci, "ERROR Transfer event TRB DMA ptr not "
> + "part of current TD\n");
> + return -ESHUTDOWN;
> + }
>
> -cleanup:
> - inc_deq(xhci, xhci->event_ring, true);
> - xhci_set_hc_event_deq(xhci);
> + if (event_seg) {
> + event_trb = &event_seg->trbs[(event_dma -
> + event_seg->dma) / sizeof(*event_trb)];
> + /*
> + * No-op TRB should not trigger interrupts.
> + * If event_trb is a no-op TRB, it means the
> + * corresponding TD has been cancelled. Just ignore
> + * the TD.
> + */
> + if ((event_trb->generic.field[3] & TRB_TYPE_BITMASK)
> + == TRB_TYPE(TRB_TR_NOOP)) {
> + xhci_dbg(xhci, "event_trb is a no-op TRB. "
> + "Skip it\n");
> + goto cleanup;
> + }
> + }
>
> - /* FIXME for multi-TD URBs (who have buffers bigger than 64MB) */
> - if (ret) {
> - urb = td->urb;
> - /* Leave the TD around for the reset endpoint function to use
> - * (but only if it's not a control endpoint, since we already
> - * queued the Set TR dequeue pointer command for stalled
> - * control endpoints).
> + /* Now update the urb's actual_length and give back to
> + * the core
> */
> - if (usb_endpoint_xfer_control(&urb->ep->desc) ||
> - (trb_comp_code != COMP_STALL &&
> - trb_comp_code != COMP_BABBLE))
> - kfree(td);
> -
> - usb_hcd_unlink_urb_from_ep(xhci_to_hcd(xhci), urb);
> - xhci_dbg(xhci, "Giveback URB %p, len = %d, status = %d\n",
> - urb, urb->actual_length, status);
> - spin_unlock(&xhci->lock);
> - usb_hcd_giveback_urb(xhci_to_hcd(xhci), urb, status);
> - spin_lock(&xhci->lock);
> - }
> + if (usb_endpoint_xfer_control(&td->urb->ep->desc))
> + ret = process_ctrl_td(xhci, td, event_trb, event, ep,
> + &status);
> + else
> + ret = process_bulk_intr_td(xhci, td, event_trb, event,
> + ep, &status);
> +
> +cleanup:
> + /*
> + * Do not update event ring dequeue pointer if ep->skip is set.
> + * Will roll back to continue process missed tds.
> + */
> + if (trb_comp_code == COMP_MISSED_INT || !ep->skip) {
> + inc_deq(xhci, xhci->event_ring, true);
> + xhci_set_hc_event_deq(xhci);
> + }
> +
> + if (ret) {
> + urb = td->urb;
> + /* Leave the TD around for the reset endpoint function
> + * to use(but only if it's not a control endpoint,
> + * since we already queued the Set TR dequeue pointer
> + * command for stalled control endpoints).
> + */
> + if (usb_endpoint_xfer_control(&urb->ep->desc) ||
> + (trb_comp_code != COMP_STALL &&
> + trb_comp_code != COMP_BABBLE))
> + kfree(td);
> +
> + usb_hcd_unlink_urb_from_ep(xhci_to_hcd(xhci), urb);
> + xhci_dbg(xhci, "Giveback URB %p, len = %d, "
> + "status = %d\n",
> + urb, urb->actual_length, status);
> + spin_unlock(&xhci->lock);
> + usb_hcd_giveback_urb(xhci_to_hcd(xhci), urb, status);
> + spin_lock(&xhci->lock);
> + }
> +
> + /*
> + * 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 (ep->skip && trb_comp_code != COMP_MISSED_INT);
> +
> return 0;
> }
>
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index 6c7e343..01da844 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -720,6 +720,14 @@ struct xhci_virt_ep {
> struct timer_list stop_cmd_timer;
> int stop_cmds_pending;
> struct xhci_hcd *xhci;
> + /*
> + * Sometimes the xHC can not process isochronous endpoint ring quickly
> + * enough, and it will miss some isoc tds on the ring and generate
> + * a Missed Service Error Event.
> + * Set skip flag when receive a Missed Service Error Event and
> + * process the missed tds on the endpoint ring.
> + */
> + bool skip;
> };
>
> struct xhci_virt_device {
> --
> 1.7.0.4
>
>
>
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