[BUG] str not used in cdns3 trace events

[Steven Rostedt]

Hi,

I'm doing updates to add __vstring (dynamically created strings in trace
events) and came across the trace events in:

  drivers/usb/cdns3/trace.h

Where there is several cases of this:

+DECLARE_EVENT_CLASS(cdns3_log_usb_irq,
+       TP_PROTO(struct cdns3_device *priv_dev, u32 usb_ists),
+       TP_ARGS(priv_dev, usb_ists),
+       TP_STRUCT__entry(
+               __field(enum usb_device_speed, speed)
+               __field(u32, usb_ists)
+               __dynamic_array(char, str, CDNS3_MSG_MAX)
+       ),
+       TP_fast_assign(
+               __entry->speed = cdns3_get_speed(priv_dev);
+               __entry->usb_ists = usb_ists;
+       ),
+       TP_printk("%s", cdns3_decode_usb_irq(__get_str(str), __entry->speed,
+                                            __entry->usb_ists))
+);

I see you create a dynamic array for "str" and even reference it in the
print with __get_str(str). But it is never assigned in TP_fast_assign().

This looks to be a bug to me. Can you explain this please?

-- Steve