[PATCH] Input: evdev - use monotonic clock for event timestamps

[Daniel Kurtz]

Using wallclock time for event timestamps subjects inter-event timing to
ntp and other clock adjustments.  This complicates userspace drivers
that use these timestamps to calculate velocities, or while processing
state transitions.

Instead, use the kernel monotonic clock for event timestamps, which is
at least guaranteed never to go backwards.

Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
---
 drivers/input/evdev.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 4cf2534..118f936 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -94,8 +94,11 @@ static void evdev_event(struct input_handle *handle,
 	struct evdev *evdev = handle->private;
 	struct evdev_client *client;
 	struct input_event event;
+	struct timespec now;
 
-	do_gettimeofday(&event.time);
+	getrawmonotonic(&now);
+	event.time.tv_sec = now.tv_sec;
+	event.time.tv_usec = now.tv_nsec/1000;
 	event.type = type;
 	event.code = code;
 	event.value = value;
-- 
1.7.3.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/