xhci: add xhci_cmd_completion trace event

This patch creates a new event class, called xhci_log_event,
and defines the xhci_cmd_completion trace event used for
tracing the commands issued to xHC that generate a completion
event in the event ring.

This info can be used, later, to print, in a human readable
way, the completion status and flags as well as the command's
type and fields using the trace-cmd tool and the appropriate
plugin.

Also, a tracepoint is added in handle_cmd_completion().

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 3393ce755b15..86971ac5851b 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1380,6 +1380,9 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
                 return;
         }
 
+        trace_xhci_cmd_completion(&xhci->cmd_ring->dequeue->generic,
+                                        (struct xhci_generic_trb *) event);
+
         if ((GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_CMD_ABORT) ||
                 (GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_CMD_STOP)) {
                 /* If the return value is 0, we think the trb pointed by