From 79915463987747e6a50dbc3c80fcfee87c7a287d Mon Sep 17 00:00:00 2001 From: Peter Hutterer Date: Tue, 4 Mar 2014 13:29:27 +1000 Subject: [PATCH] Document the FORCE_SYNC behavior a bit better Signed-off-by: Peter Hutterer (cherry picked from commit 0deacd5c1ea587350e8acb4e760ed1711ad82a45) --- libevdev/libevdev.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/libevdev/libevdev.h b/libevdev/libevdev.h index 898e919..5398061 100644 --- a/libevdev/libevdev.h +++ b/libevdev/libevdev.h @@ -699,6 +699,13 @@ enum libevdev_read_status { * dropped after libevdev updates its internal state and event processing * continues as normal. * + * If a device has changed state without events being enqueued in libevdev, + * e.g. after changing the file descriptor, use the @ref + * LIBEVDEV_READ_FLAG_FORCE_SYNC flag. This triggers an internal sync of the + * device and libevdev_next_event() returns @ref LIBEVDEV_READ_STATUS_SYNC. + * Any state changes are available as events as described above. If + * @ref LIBEVDEV_READ_FLAG_FORCE_SYNC is set, the value of ev is undefined. + * * @param dev The evdev device, already initialized with libevdev_set_fd() * @param flags Set of flags to determine behaviour. If @ref LIBEVDEV_READ_FLAG_NORMAL * is set, the next event is read in normal mode. If @ref LIBEVDEV_READ_FLAG_SYNC is