xhci: Add additional dynamic debug to follow URBs in cancel and error cases.

Add more debugging messages to follow what happends to a URB internally
in special cases like URB cancel, halted endpoints and endpoint reset.

Helps tracking issues like URB never given back by host.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210820123503.2605901-6-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9017986..8be4ba3 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -830,9 +830,14 @@ static void xhci_giveback_invalidated_tds(struct xhci_virt_ep *ep)
 
                ring = xhci_urb_to_transfer_ring(ep->xhci, td->urb);
 
-               if (td->cancel_status == TD_CLEARED)
+               if (td->cancel_status == TD_CLEARED) {
+                       xhci_dbg(ep->xhci, "%s: Giveback cancelled URB %p TD\n",
+                                __func__, td->urb);
                        xhci_td_cleanup(ep->xhci, td, ring, td->status);
-
+               } else {
+                       xhci_dbg(ep->xhci, "%s: Keep cancelled URB %p TD as cancel_status is %d\n",
+                                __func__, td->urb, td->cancel_status);
+               }
                if (ep->xhci->xhc_state & XHCI_STATE_DYING)
                        return;
        }
@@ -850,6 +855,10 @@ static int xhci_reset_halted_ep(struct xhci_hcd *xhci, unsigned int slot_id,
                goto done;
        }
 
+       xhci_dbg(xhci, "%s-reset ep %u, slot %u\n",
+                (reset_type == EP_HARD_RESET) ? "Hard" : "Soft",
+                ep_index, slot_id);
+
        ret = xhci_queue_reset_ep(xhci, command, slot_id, ep_index, reset_type);
 done:
        if (ret)
@@ -883,7 +892,8 @@ static int xhci_handle_halted_endpoint(struct xhci_hcd *xhci,
        }
 
        if (ep->ep_state & EP_HALTED) {
-               xhci_dbg(xhci, "Reset ep command already pending\n");
+               xhci_dbg(xhci, "Reset ep command for ep_index %d already pending\n",
+                        ep->ep_index);
                return 0;
        }
 
@@ -922,9 +932,10 @@ static int xhci_invalidate_cancelled_tds(struct xhci_virt_ep *ep)
 
        list_for_each_entry_safe(td, tmp_td, &ep->cancelled_td_list, cancelled_td_list) {
                xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
-                               "Removing canceled TD starting at 0x%llx (dma).",
-                               (unsigned long long)xhci_trb_virt_to_dma(
-                                       td->start_seg, td->first_trb));
+                              "Removing canceled TD starting at 0x%llx (dma) in stream %u URB %p",
+                              (unsigned long long)xhci_trb_virt_to_dma(
+                                      td->start_seg, td->first_trb),
+                              td->urb->stream_id, td->urb);
                list_del_init(&td->td_list);
                ring = xhci_urb_to_transfer_ring(xhci, td->urb);
                if (!ring) {
@@ -1079,6 +1090,8 @@ static void xhci_handle_cmd_stop_ep(struct xhci_hcd *xhci, int slot_id,
                        return;
                case EP_STATE_RUNNING:
                        /* Race, HW handled stop ep cmd before ep was running */
+                       xhci_dbg(xhci, "Stop ep completion ctx error, ep is running\n");
+
                        command = xhci_alloc_command(xhci, false, GFP_ATOMIC);
                        if (!command)
                                xhci_stop_watchdog_timer_in_irq(xhci, ep);
@@ -1400,7 +1413,12 @@ static void xhci_handle_cmd_set_deq(struct xhci_hcd *xhci, int slot_id,
                ep_ring = xhci_urb_to_transfer_ring(ep->xhci, td->urb);
                if (td->cancel_status == TD_CLEARING_CACHE) {
                        td->cancel_status = TD_CLEARED;
+                       xhci_dbg(ep->xhci, "%s: Giveback cancelled URB %p TD\n",
+                                __func__, td->urb);
                        xhci_td_cleanup(ep->xhci, td, ep_ring, td->status);
+               } else {
+                       xhci_dbg(ep->xhci, "%s: Keep cancelled URB %p TD as cancel_status is %d\n",
+                                __func__, td->urb, td->cancel_status);
                }
        }
 cleanup: