usb: udc: Add trace event for usb_gadget_set_state

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@google.com>
Link: https://lore.kernel.org/r/20250818082722.2952867-1-khtsai@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index d709e24c1fd4228c47f877d097faf987975ac392..e28fea614496dc41948de8638e06830cb4113a4f 100644 (file)
--- 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 4e334298b0e8a75a925093b00875aa78708551eb..fa3e6ddf0a12809245a69808ae8f35bf67db9dfe 100644 (file)
--- 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)