DUMMY_CB(4)

NAME
dummy_cb - CardBus dummy device driver

SYNOPSIS
insmod dummy_cb.o [pc_debug=n]

DESCRIPTION
The dummy_cb module is a sort of "point enabler" for CardBus cards. When it is bound to a card, it configures that card, but otherwise does not do anything. It may be useful for cards that have Hot Plug PCI kernel drivers, but do not have CardBus client drivers in the pcmcia-cs package. Hot Plug PCI drivers expect the kernel to handle CardBus card configuration; instead, drivers in the pcmcia-cs package rely on the cb_enabler module to do that.

To use dummy_cb, edit /etc/pcmcia/config.opts and add one or more card descriptions, like:

    card "Western Digital 1394 Adapter"
      pci 0x1033, 0x00cd
      bind "dummy_cb"

This will override any driver bindings in the main config file. After restarting cardmgr, then, insertion of these cards should load dummy_cb. After that, the Hot Plug PCI driver can be loaded.

Before ejecting a card using dummy_cb, it is important to manually unload the corresponding Hot Plug PCI driver. Since cardmgr cannot notify this sort of driver about removal events, bad things can happen if the Hot Plug PCI driver is not unloaded first. Yes this is rather fragile. Ideally, people will use Hot Plug PCI drivers with the kernel PCMCIA subsystem, but dummy_cb is meant as a quick fix for situations where that is not possible.

PARAMETERS

pc_debug=n
    Selects the PCMCIA debugging level. This parameter is only available if the module is compiled with debugging enabled. A non-zero value enables debugging.

AUTHOR
David Hinds - dahinds@users.sourceforge.net

SEE ALSO
cardmgr(8), pcmcia(5).