K 10
svn:author
V 3
pho
K 8
svn:date
V 27
2012-06-29T14:14:49.631168Z
K 7
svn:log
V 324
MFC: r237219

In tty_makedev() the following construction:

dev = make_dev_cred();
dev->si_drv1 = tp;

leaves a small window where the newly created device may be opened
and si_drv1 is NULL.

As this is a vary rare situation, using a lock to close the window
seems overkill. Instead just wait for the assignment of si_drv1.

END