Hi All

m trying to understand PCI interface in linux enviourment.Here is output of lspci -vv

Please explain what all PCI specification i can get from this command?
Why there are 4 region ,1 for I/O port and 3 for memory? When v Can have less then 4 region?
Why they are disbaled?

Thanks and Regards

http://www.xml.com/ldd/chapter/book/ch15.html#t1
... or read the PCI specification - start [url=http://en.wikipedia.org/wiki/Peripheral_Component_Interconnect]here[/i] then read the actual paper.

There are four regions set out that way because that's how the manufacturer wanted it done. There are usually HW reasons for the exact layout. They are disabled because nobody enabled them. Maybe they are not used? It is not unusual that a devices full capabilities are not enabled on a motherboard. It's usually easier than making a separate chip for each combination needed.

You have not said which pci device this is - but it looks like the layout of cache memory to me. A VGA card or an Audio controller? Different bunches of memory get assigned to different purposes. (Anyone?)

Thanks Simon

M using PCI 372
How can i make pci device enable?

Do all PCI device are disable on startup and v have to enable them always ??

A LAN card?

If the functionality is available, it is enabled by passing options to the driver and/or manipulating the BIOS.
Remember, lspci just gets it's info from the device ROM... "disabled" entries may represent empty chip slots on the board.

If you want to show what the card says it is - you need to show me the first line in it's lspci listing.

Is there some functionality you need from the card which you are not getting?

I think this is a line above that
02:02.0 Communication controller: Performance Technologies, Inc. Device 372b (re
v 05)
Subsystem: Performance Technologies, Inc. Device 372b

OKIE if it is diabled but how come i made it anable ....

here m just trying to access the pci memory space of this device and write or read from it ...

i think for that too i hve to write some sort of driver which use kernel service and i cnt do that from the application layer i.e from outside kernel.

Any more pointers

I'm going to have to ask you to clean up your text. Please write whole words and complete grammatical sentences. I just don't understand most of what you are writing. I can probably figure it out, but I'm doing this is spare time and there are hundreds of other people to help out.

When you want high quality answers, please post high quality questions - if you cannot be bothered to write "I cannot" instead of "i cnt" (for four additional keystrokes) then why should I be bothered helping you out?

This stuff is all explained in the LQ guidelines and the "advice" part of my sig.

From what I can make out, you need to review how PCI actually works. The PCI memory space is not the sort of thing that is supposed to be available for anything other than the PCI card.

http://www.fpga4fun.com/PCI1.html
... page two talks about implimenting some RAM on PCI. It's windows-specific, but uses free drivers to open the IO space and is actually pretty illuminating if terse. Google for other tutorials to fill in the gaps.

Basically - you need to read the specification - you are looking at some pretty low level programming here.

Thanks a ton for your help
I made myself clear this time with no "cnt" stuff.