While the userspace program can be notified of gadget state changes, timing issue can lead to missed transitions when reading the state value. Introduce a trace event for usb_gadget_set_state to reliably track state transitions. Signed-off-by: Kuen-Han Tsai <khtsai@xxxxxxxxxx> --- drivers/usb/gadget/udc/core.c | 1 + drivers/usb/gadget/udc/trace.h | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index d709e24c1fd4..e28fea614496 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1125,6 +1125,7 @@ void usb_gadget_set_state(struct usb_gadget *gadget, { gadget->state = state; schedule_work(&gadget->work); + trace_usb_gadget_set_state(gadget, 0); } EXPORT_SYMBOL_GPL(usb_gadget_set_state); diff --git a/drivers/usb/gadget/udc/trace.h b/drivers/usb/gadget/udc/trace.h index 4e334298b0e8..fa3e6ddf0a12 100644 --- a/drivers/usb/gadget/udc/trace.h +++ b/drivers/usb/gadget/udc/trace.h @@ -81,6 +81,11 @@ DECLARE_EVENT_CLASS(udc_log_gadget, __entry->ret) ); +DEFINE_EVENT(udc_log_gadget, usb_gadget_set_state, + TP_PROTO(struct usb_gadget *g, int ret), + TP_ARGS(g, ret) +); + DEFINE_EVENT(udc_log_gadget, usb_gadget_frame_number, TP_PROTO(struct usb_gadget *g, int ret), TP_ARGS(g, ret) -- 2.51.0.rc1.163.g2494970778-goog