A patch for Theodore Ts'o's Linux serial driver which adds very ugly support for Actiontec's 56K Internal PCI Call Waiting Modem. This patch causes the driver to be hard-wired to auto-detect this modem. I believe that the Lucent Venus chipset may be buggy, and am currently working with Lucent, Actiontec, and Theodore Ts'o to fix it.
I have written open letters to Agere and Actiontec.

I wrote a kernel module to demonstrate the problems I am having with the Venus chipset. The module writes a value to the interrupt enable register (IER) on one's modem. It then immediately reads the value stored in the IER. Reading a value from the IER that does not equal the value written to it seems to represent a bug in the chipset. Theodore Ts'o's serial driver makes extensive use of a modem's IER when it performs detection operations; thus detecting a Venus-based modem often fails.

To try this test on your own machine, download the kernel module and read the directions included in the source file.

Assistant Professor

My research interests include free and open source software, system security, and network security.