serial-5.05-actiontec

serial-5.05-actiontec
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.

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W. Michael Petullo

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