I'm currently using an ioctl call to get notification on changes
in some register. I just want to know (as this may effect my
implementation) whether ioctl unblocks when one closes
the file descriptor on which the ioctl call is made. Currently
I'm blocking infinitely (which is what I prefer). I'm aware
of the fact that one can use select and use another descriptor
to unblock the original, but currently the driver (over which I
have no control) has not implemented select properly.