After adding OS trace to yaffs2, I saw that sync does a call to yaffs_sync_fs,
but  it is a nop.

This mean sync syscall doesn't flush the yaffs2 cache and data it lost on
unclean umount.


Calling yaffs_FlushEntireDeviceCache in yaffs_sync_fs seems to make sync working.
What do you think of that ?



Matthieu