Commit ea4e289c authored Mar 18, 2015 by Uwe Kleine-König Committed by Sasha Levin Apr 16, 2015

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



[ Upstream commit 391949b6f02121371e3d7d9082c6d17fd9853034 ]

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>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent 7cc582d4

drivers/spi/spi.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1073,13 +1073,14 @@ 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);