fsi: gpio: Trace busy count

An observation from trace output of the existing FSI tracepoints was
that the remote device was sometimes reporting as busy. Add a new
tracepoint reporting the busy count in order to get a better grip on how
often this is the case.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Eddie James <eajames@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>

drivers/fsi/fsi-master-gpio.c

@@ -401,6 +401,9 @@ static int poll_for_response(struct fsi_master_gpio *master,
 		break;
 	}
 
+	if (busy_count > 0)
+		trace_fsi_master_gpio_poll_response_busy(master, busy_count);
+
 	/* Clock the slave enough to be ready for next operation */
 	clock_zeros(master, FSI_GPIO_PRIME_SLAVE_CLOCKS);
 	return rc;

include/trace/events/fsi_master_gpio.h

@@ -64,6 +64,22 @@ TRACE_EVENT(fsi_master_gpio_break,
 	)
 );
 
+
+TRACE_EVENT(fsi_master_gpio_poll_response_busy,
+	TP_PROTO(const struct fsi_master_gpio *master, int busy),
+	TP_ARGS(master, busy),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(int,	busy)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->busy = busy;
+	),
+	TP_printk("fsi-gpio%d: device reported busy %d times",
+		__entry->master_idx, __entry->busy)
+);
+
 #endif /* _TRACE_FSI_MASTER_GPIO_H */
 
 #include <trace/define_trace.h>