Introduction

Supported Linux Kernels

• 2.4-based kernels on Intel and Alpha platforms
• 2.2-based kernels on Intel and Alpha platforms
• 2.0-based kernels equal or newer than 2.0.36 on Intel platforms

The driver package has been tested with the following unmodified Linux distributions:

• RedHat 6.2
• RedHat 7.0
• SuSe 7.1
• SuSe 7.0
• SuSe 6.4
• Conectiva 6.0
• TurboLinux 6.1 workstation
• TurboLinux 6.0 server
• Mandrake 7.2

Though unsupported, the driver package has been noted to run in the following modified distribution environments:

• RedHat 6.2 (w/ 2.4.0 kernels installed)
• RedHat 7.0 (w/ 2.4.3 kernels installed)

Supported Products

• Digi One RealPort Device Server
• EtherLite 2
• EtherLite 160
• EtherLite 162
• PortServer 8
• PortServer 16
• PortServer II 16
• PortServer TS 2
• PortServer TS 4
• PortServer TS 8
• PortServer TS 16

Enhancements

• Added 2.4 kernel support.
• Increased support for Digi's ethernet-based serial connectivity family; including Digi One, EtherLite, and PortServer products.
• Added support for arbitrary integer baud rates via the "ditty-rp" utility.
• Detailed information about the type and version of configured remote devices may now be obtained via the "/proc/dgrp/nodeinfo" file.

Bug Fixes

• A memory corruption problem which would cause sysem instability has been eliminated.
• Unexpected pauses and loss in port traffic as a result of a network buffer overflow have been resolved.
• Removed references to invalid email addresses.
• Driver now handles RedHat 7.0 (kgcc vs. gcc).
• The GUI tool now displays the DCD signal when viewing ports.
• RealPort ports now match other Linux serial ports for default settings, as well as making all port settings "sticky". As a result of this change, CLOCAL is now on by default.
• Configuration scripts now will remove the "/dev" files if a PortServer is unconfigured.
• Only physical line drops will be detected as a "hangup" condition... the driver would previously treat a change from CLOCAL to -CLOCAL as a carrier transition.
• Startup scripts will now be installed in "/etc/init.d" if "/etc/rc.d/init.d" does not exist.
• RPM installation will not "error out" if "chkconfig" (a RedHat tool) does not exist on the system.
• A message has been added to the RPM installation to communicate to users whether the installation scripts have been added or not.
• On newer systems, RPM would inadvertently strip the driver module of its symbols, causing it to fail. The module is no longer stripped.

Known Limitations

• There is a known incompatibility between our driver and some Linux distributions which ship a custom modified 2.4 kernel. The problem manifests itself with device driver usage counts which never decrease, possible loss of use of some numbers of ports, and possible system instability. The root cause is in the modification of the kernel, which makes a change to an internal interface and introduces an incompatibility. Customers with this problem are encouraged to download and install an "official" Linux kernel from "kernel.org".
• There is a problem with the SBRK ioctl. When a BRK is sent no more data is transmitted until the port is closed.
• The ports on EM modules are observed to perform at a slightly reduced speed during throughput testing.
• There is no support as of yet for the transparent print devices.
• The ditty PRINTER option is not yet supported.

Printers

Ditty

Configuration and Startup

The software package includes two startup scripts in either the /etc/rc.d/init.d or /etc/init.d directories named "dgrp_daemon" and "dgrp_ditty". These scripts will be executed at startup automatically if the "chkconfig" tool is present on the system during the post installation phase of the driver install. Otherwise, these scripts must be manually added to the system startup.

History

• Version 0.1-1 - pilot release in January 1999
• Version 0.1-3: added new scripts to autoload the driver on system startup and initialize any PortServers configured in /etc/dgrp.backing.store
• Version 0.1-4: decided to install dgrp.o to the /usr/bin/dgrp directory, and then link in the postinstall phase to a suitable /lib/modules/*/misc directory. This avoids the problem of having the path to dgrp.o hardcoded in the spec file.
• Version 0.1-5: a minimum break time of 250ms is now enforced. A PPP hang problem was resolved. Continued enhancements of the packaging.
• Version 0.1-7: A first pass at cleaning up the code was completed for beta release. All driver build warnings have been fixed. Appropriate part numbers have been correctly placed in the appropriate documents. A useful driver revision number is now placed in the console log when the module is loaded.
• Version 1.0-0: Added a new proc file: /proc/dgrp/info. This file allows one to determine the value of a number of state variables associated with the driver, including the driver revision. Continued refinement of the GUI. The GUI is now distributed as a single file, rather than a collection of "tcl" files. dgrp_cfg_node now does validity checking of its ID and COUNT parameters.