spi: trigger trace event for message-done before mesg->complete

commit 391949b6f02121371e3d7d9082c6d17fd9853034 upstream.

With spidev the mesg->complete callback points to spidev_complete.
Calling this unblocks spidev_sync and so spidev_sync_write finishes. As
the struct spi_message just read is a local variable in
spidev_sync_write and recording the trace event accesses this message
the recording is better done first. The same can happen for
spidev_sync_read.

This fixes an oops observed on a 3.14-rt system with spidev activity
after

	echo 1 > /sys/kernel/debug/tracing/events/spi/enable

.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index d9a59a0464cd6ec65600f67a5c53ea4393c990f7..577605167be2d3e6e4303f0e9d96bb1e7db98155 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1053,13 +1053,14 @@ void spi_finalize_current_message(struct spi_master *master)
                                "failed to unprepare message: %d\n", ret);
                }
        }
+
+       trace_spi_message_done(mesg);
+
        master->cur_msg_prepared = false;
 
        mesg->state = NULL;
        if (mesg->complete)
                mesg->complete(mesg->context);
-
-       trace_spi_message_done(mesg);
 }
 EXPORT_SYMBOL_GPL(spi_finalize_current_message);