Re: Slot number in Desk-top - huh?

["Danny Lobo" <lobod@netscout.com>]

I agree - there is no way to figure out the physical slot in which a PCI
board is plugged in. However, if your application is always using the same
motherboard, you may be able to experimentally figure out the slot
assignments since the PCI Bios on a given motherboard generally follows a
pattern in assigning the bus #s to the PCI cards. Again this would not work
if your application has to work across several motherboards.

Thanks,
Danny Lobo,
NetScout Systems Inc


   My private answer to him went as follows:

   You can't.  This is a fundamental problem with PCI and it is a problem
   we
   have all the time.  On a PCI bus, you can figure what board is plugged
   in,
   but it is impossible to determine which physical slot the board is
   plugged
   into.  This is all PCI, not just Sun.  This can be quite troublesome if
   you
   put two of the same boards into a system and, for example, they get
   cabled
   differently to something external.

   The only way to solve this is to put a DIP switch on the PWB or add some
   sort of an ID to the circuit.  Upon installation, the user (or other)
   must
   tell the driver which of these ID's in connected to which function.

   Now I state again in clearer prose:  Across platforms, it is impossible
   in
   PCI to correctly determine the physical location of a PCI resource
   without
   some external intervention.

   Agree/Disagree?



                                                                                                                                         
                      Mike Dini                                                                                                          
                      <mdini@dinigroup.        To:       pci-sig@znyx.com@SMTP@Exchange                                                  
                      com>                     cc:                                                                                       
                                               Subject:  Slot number in Desk-top  - huh?                                                 
                      01/08/2003 02:09                                                                                                   
                      PM                                                                                                                 
                                                                                                                                         
                                                                                                                                         



I'm confused as to how the original question deviated into the IRQ's,
unless I misunderstood the original question.  I thought Dinesh asked the
following question (paraphrasing):

    I have a board plug into PCI/PCIX/ et al.
    How does the driver determine the physical
    location of that board?

My private answer to him went as follows:

You can't.  This is a fundamental problem with PCI and it is a problem we
have all the time.  On a PCI bus, you can figure what board is plugged in,
but it is impossible to determine which physical slot the board is plugged
into.  This is all PCI, not just Sun.  This can be quite troublesome if you
put two of the same boards into a system and, for example, they get cabled
differently to something external.

The only way to solve this is to put a DIP switch on the PWB or add some
sort of an ID to the circuit.  Upon installation, the user (or other) must
tell the driver which of these ID's in connected to which function.

Now I state again in clearer prose:  Across platforms, it is impossible in
PCI to correctly determine the physical location of a PCI resource without
some external intervention.

Agree/Disagree?

>|
>| Hi Experts,
>|
>| I have a basic qry.
>| In a desk-top environment, is there a mechanism to find out which
>| PCI card/resource is plugged in to which slot ? In other words, is
>| it possible in OS level  to read slot number of a particular PCI
>| card plugged in to a desk-top ?  Assume the machine is running in
>| Solaris/Linux.
>| Any one experienced similar problems ?
>|
>| Thanks in advance
>|
>| Dinesh