K 10
svn:author
V 7
gehenna
K 8
svn:date
V 27
1999-07-25T18:35:35.000000Z
K 7
svn:log
V 375
MFC: from rev. 1.21 and 1.23

o Call ums_disable() to abort the pipe.
o Do not wake up processes which has been waiting or polling for mouse
  data.  It won't be available anymore.
o Add non-blocking I/O on read
o Add checks to make sure we do not dereference the softc when not found
  because the device has been removed.

Requested by:	Kazutaka YOKOTA
OKed by:	Nick Hibma

END