I have a 64 port siemens wavecom modem pool connected via USB to a Computer running Ubuntu. I am trying to create a python script that interacts with the modems for some automated testing project but Ubuntu can only detect 32 devices. Is there any way I can increase the number of modems it can detect?


Believe it's compiled into the kernel.

grep CONFIG_SERIAL_8250_RUNTIME_UARTS /boot/config*

See Serial Tips And Miscellany

Number of Serial Ports Supported If you have more than 4 (or possibly 2) serial ports, then you must insure that the kernel knows this. It can be done by configuring the kernel when compiling or by a parameter given to the kernel when it starts (boot-prompt or kernel command line).

The kernel configuration parameters: CONFIG_SERIAL_8250_RUNTIME_UARTS=4 and CONFIG_SERIAL_8250_NR_UARTS=4 set the maximum number of ordinary serial ports (UARTs) equal to 4. If you have more than 4 ordinary serial ports, then you need to change the 4 to whatever. But you may override this via the kernel command line for example: nr_uarts=16 (if serial support built into the kernel) or 8250.nr_uarts=16 (if serial support is via a module). The boot loader such as lilo or grub can be told to do this.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.