Migrating Config from 2.5 to 2.7

If you use the Parallel Port driver there are some changes. Older versions of the LinuxCNC hal_parport driver conflicted with the Linux parport_pc driver. This required two mitigation techniques, prevent parport_pc from loading, and load another LinuxCNC driver called probe_parport before loading hal_parport.

The LinuxCNC hal_parport driver now cooperates well with the Linux parport_pc driver, and these mitigation techniques are no longer needed or useful. In 2.7, the probe_parport driver has been removed from LinuxCNC.

This means configs that use the parallel port may need to be updated in the following ways:

Make sure LinuxCNC does not prevent the Linux parport_pc driver from loading. Older versions of LinuxCNC would blacklist parport_pc in /etc/modprobe.d/linuxcnc.conf (or /etc/modprobe.d/emc2.conf for even older versions of LinuxCNC). Comment out any lines in either of those files that looks like this: 
install parport_pc /bin/true

grep -r port .
./my-mill.hal:loadrt hal_parport cfg="0x378 out"
./my-mill.hal:addf parport.0.read base-thread
./my-mill.hal:addf parport.0.write base-thread
./my-mill.hal:net xstep           => parport.0.pin-01-out
./my-mill.hal:net xenable         => parport.0.pin-02-out
./my-mill.hal:net ydir            => parport.0.pin-03-out
./my-mill.hal:net zdir            => parport.0.pin-04-out
./my-mill.hal:net zstep           => parport.0.pin-05-out
./my-mill.hal:net xenable         => parport.0.pin-06-out
./my-mill.hal:net xdir            => parport.0.pin-07-out
./my-mill.hal:net ystep           => parport.0.pin-08-out
./my-mill.hal:net spindle-cw      => parport.0.pin-09-out
./my-mill.hal:net xenable         => parport.0.pin-14-out
./my-mill.hal:net xenable         => parport.0.pin-16-out
./my-mill.hal:net xenable         => parport.0.pin-17-out