RE: PCI modems

["Atul Chitnis" <achitnis@xxxxxxxxxxxxxxxx>]

>   7  ``PCI Modems'' seldom work under Linux
>
> It does not say that all the PCI modems will not work, but PCI modems
> definitly are a problem
> under Linux.

This is a generalisation I find difficult to accept. It is like saying "PCI
display cards seldom work under Linux". That may have been true before, but
not now. Whoever wrote that statement wasn't thinking right.

PCI is an interface like AGP and ISA. All three are supported under Linux.
PCI and AGP support, being newer, is still slightly "raw", but it is getting
there. On bootup, the machine initialises the PCI cards and Linux can easily
query the cards for their configs. Modems are actually the easiest of
devices to address once you know the IO address and IRQ are known.

The issue arises if the modem is a *WinModem*. These nasty devices don't
have any brains at all (you cannot write an "AT" to them and expect to get
back an "OK"). The other issue is high-memory addresses - this is not a
problem with the modem - it is a problem with Linux (just like the 2 GB file
size limit) that is being worked on and will be fixed real soon now.

The real test here is - if the PCI modem assigns an IO address in
0x[32][FE]8 and the IRQ somewhere under 15, it will happily work with
current Linux versions. If it uses high/shared addresses, it will not work
today, but *will* work as soon as the kernel developers get around to
addressing this issue (they have to - hardwired address ranges are a
historical anomaly like the 640K RAM limit).

Generalising that all PCI Modems seldom work with Linux is an unqualified
and unconditional statement that is bound to cause problems not in the
future, but right now, where motherboards are beginning to appear without
ISA slots, and all future devices will be either USB/FireWire or PCI based.

Atul


- --------------------------------------------------------------------
For more information on Linux in India visit http://www.linux-india.org/
Linux India is NOT a forum for Microsoft/India/Pakistan/US/UK bashing.
Flame baits will not be tolerated.  If you can appreciate satire read
http://www.templetons.com/brad/emily.html

------------------------------