5. FAQ

5.1 I have a winmodem. Will it work under Linux?

Probably not. Please see the section "Which Linmodem hardware is supported?" above, and check the Linux Modem Compatibility database at Rob Clark's site.

5.2 I get a "device or resource busy" error.

• If you have an ISA modem, did you use the isapnptools to allocate IRQ and DMA resources to the card? See "ISA Plug-n-Play", above, for more information.
• If you do setserial -agv /dev/ttyS*, does it return something sane for your device file? If not, see the "Modifying your serial port configuration" section above.
• Otherwise, double-check that you created the device file correctly, and try to eliminate any IRQ conflicts you might have. If all looks well, but it still doesn't work, check the Linmodems.org mailing list to see if someone else has (and has perhaps fixed) the same problem, or try to fix it yourself and inform others of your results.

5.3 I get unresolved symbols when fixscripting/insmoding.

Unresolved symbols are a true danger of version mismatching and are, in general, bad, but are also almost inevitable with binary modules. If the fixscript reports unresolved symbols, or the module does not work despite the unresolved symbols, you may be out of luck with that kernel/module combination; however, a few common cases involve symbols like:

• slhc_xxxx: You probably need to insmod the slhc module before inserting the modem/ppp modules.
• printk, jiffies: Your kernel may be compiled with SMP enabled. None of the binary modules are known to be SMP-safe, and will probably only work on a single-processor machine with a single-processor kernel, i.e. SMP disabled. You should try recompiling your kernel or otherwise obtaining a version with SMP disabled. (Thanks to Tom Reinertson (treinertson(at)uswest.net))
• tty_xxxx with esscom.o: Earlier fixscripts were not able to handle the version-specific symbols in this module. A preliminary, expanded fixscript has been included in this version of the HOWTO which should be able to fix this module as well. It assumes you have a fairly recent version of the depmod utility; later versions will improve the reliability and flexibility of these new parts of the fixscript code. Look for more recent versions of this HOWTO http://walbran.org/sean/linux/linmodem-howto.html to see if the script has been improved.

5.4 The ppp2214.o doesn't work with my SuSE (or other) kernel.

The 2.2.14 ppp.o trick appears to be sensitive to kernel versions and configurations. Try to obtain one that matches your kernel as well as possible, and if that doesn't work, try to obtain one from any other source you can find. For SuSE 7.0, Christoph Hebeisen has posted a 2.2.14 ppp.o pre-fixed for the SuSE 2.2.16 kernel at his site, http://www.physcip.uni-stuttgart.de/heby/computer/ltmodem/ , which should work.

5.5 My PCTel modem doesn't work.

• Do you need to give the module a country code parameter? See the appendix.
• Are you using the right driver module? There are a few PCTel drivers around (see the section "Which Linmodem hardware is supported?" above). You might try one of the others and see if that helps.

5.6 The modem dials and connects fine, but then it drops the connection.

This is an often-reported problem that may not have a solution.

It is possible that the module is installed correctly and is working, but that you have a problem with your ppp configuration. See "Configure your PPP dialer", above, for more information.

It has been reported that, with some kernel/module mismatches, a program like kppp will give this error, while an alternative like wvdial does not, for the same modules and hardware. You may wish to try a different ppp dialer and see if that helps.

If none of these helps, you may wish to consider trying to use a kernel version which is closer to the module. Otherwise, try the mailing list at Linmodems.org for help.

5.7 I get a kernel panic on closing the connection or unloading the driver.

There are a couple of possible solutions to this, neither of which may work:

• Try a different ppp dialer (wvdial, kppp).
• Configure the module so that it stays in the kernel, i.e. so that it is not unloaded.

5.8 Nothing seems to work. To whom can I turn for help?

• Double-check that the modem you have is actually supported by the module you have. See "Which Linmodem Hardware Is Supported?" above.
• Try to determine at which stage of the installation process things break down. Check the man pages on the commands used in that stage and see if you can determine the source of the problem.

If all seems lost, please see the section "Troubleshooting", below , and consider sending a message with the complete information described there to the mailing list at Linmodems.org.

5.9 Who wrote the driver for my winmodem, and how do I contact him/her?

Probably somebody on contract to the manufacturer, who probably does not have the authority the update/release/change the source code, and who probably doesn't have time to reply to your email in any case. See, for example, http://lwn.net/1999/1209/a/lucent.html