5. General - Kernel/Driver issues

5.1 Do I need to configure CONFIG_PNP in the kernel ?

This applies to 2.1.xxx and later kernels. They now include a configuration option CONFIG_PNP. This is intended to enable the kernel to configure some PnP devices, but there is little or no support in the kernel (2.1.131).

If you're using isapnptools, it would probably be better to set this value to N, to prevent bad interactions when it does do something.

5.2 I've configured my ... using isapnptools, but the kernel doesn't recognise it.

There are lots of possibilities for this, just remember:

1. isapnp must be run before the driver initialises, unless a separate program is available to initialise drivers later (eg. setserial). (See the README.modules file provided with the distribution).
2. The settings for the board specified to isapnp must match those of the driver for the board.
3. You must load a driver for the card. It is not sufficient to have an entry in dev/.

5.3 I get the error message "... module support already loaded" when trying to load the ... module.

This means that the driver module has already been loaded or is built into the kernel. Try typing "cat proc/devices/" to see what devices are already loaded before insmodding the driver.

This could also be due to not rebooting after rebuilding the kernel with module support for the required driver.

5.4 I'm having trouble getting interrupts to work.

A bug has been discovered in isapnp for Version 1.11 of isapnptools, relating to the setting of interrupt edges. This is unlikely to be a problem for most hardware because the hardware doesn't allow anything other that +ve edge interrupts, however, as Kevin Bowman has pointed out, some hardware, such as that using the Fujitsu MB86701 does allow the interrupt line to be programmed. In this case, try upgrading to Version 1.13 or later.

5.5 I've configured the card, but /proc/interrupts still shows the interrupt as unused.

/proc/interupts still lists the IRQ I am choosing as unused and the same for the IO ports. Does this mean the installation has failed ?

Not necessarily. Until you load a device driver that uses them, the resources remain unused. You can use pnpdump -d to check the programming if you have a version that supports the --dumpregs option.

5.6 The driver for my card cannot be built as a module.

If the driver you want to use can only be built into the kernel, then you may want to consider using the DOS version of isapnptools, then booting Linux via loadlin. See README.DOS in the distribution for details.

5.7 As soon as I run isapnp, my machine locks up.

You have SCSI disks on a PnP adapter card - right ? In this case you must be doing a full reset of the ISA PnP hardware, which is making the disks disappear. Alternatively, you may have a PnP network card and a built-in kernel driver.

Make sure your configuration file doesn't contain ( ISOLATE PRESERVE).

For the network card case, you can still do a full ISA PnP reset if you remove the network card driver from the kernel and use a module instead (and load it after running isapnp).

5.8 How can I stop isapnp and pnpdump using certain addresses for the READPORT.

Get isapnptools 1.16 or later, and put the port addresses you want to avoid in the /etc/isapnp.gone file. This assumes you want to try lots of addresses, but skip certain ones. If you just want to use a specific address, specify the address as the last argument.