[ros-kernel] Accessing floppy drive without floppy present hangs ReactOS

[Ge van Geldorp]

When opening "My Computer" (but also doing a "dir a:" from a blue screen
command prompt) ReactOS stops responding when there is no disk inserted
in the drive. This is pretty bad, as after a default install there are
only two icons on the desktop and you can pretty much expect the user to
double-click the "My Computer" icon. It seems very likely that there
will be no floppy in the drive.

For the moment I've disabled the floppy driver in the release branch.
The floppy driver wasn't much use yet anyway, since there's no media
change detection. I think not having an A: drive is better than having
ReactOS lockup on "My Computer" doubleclicks.

What I've found tracing this problem is that the drive is successfully
re-calibrated. The DPRINT at line 116 in floppy/isr.c is executed. Then
the "Read ID Mark" command is issued to the controller, but this command
never completes. I guess at some point a timer should be activated, just
not sure where or how.

Gé van Geldorp.