SIOCGIFMAP silently broken?

SIOCGIFMAP silently broken?

[Martin Wilck]

Hi,

we are using a server management software that uses the irq information
returned by the SIOCGIFMAP ioctl to correlate network interfaces with
LAN hardware.

The code for SIOCGIFMAP if net/core/dev.c simply returns netdev->irq 
which isn't set by most actual LAN drivers any more, and it seems to
be common opinion that setting netdev->irq is either optional or even 
wrong (http://www.ussg.iu.edu/hypermail/linux/kernel/0407.3/1292.html).

Consequently, the SIOCGIFMAP ioctl reports bogus IRQ values for most 
hardware; it is therefore unreliable.

Would it be possible to fix the ioctl such that it returns the correct 
irq value, e.g. be using the irq field of the associated struct pci_dev?

If not, I'd consider it better to deprecate netdev->irq officially and 
always return bogus so that people stop using it.

In both cases, the netdev->irq field isn't used anymore; perhaps it 
should be officially deprecated and/or removed?

Regards
Martin

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Re: SIOCGIFMAP silently broken?

[David S. Miller]

On Mon, 31 Jan 2005 15:57:09 +0100
Martin Wilck <martin.wilck@fujitsu-siemens.com> wrote:

> In both cases, the netdev->irq field isn't used anymore; perhaps it 
> should be officially deprecated and/or removed?

It is used for explicitly setting the IRQ value on hardware
where doing so automatically via probing may not be %100
reliable, such as on ISA.

Another way to do what you're trying to do is to look for
the string name of the device you are interested in within
the output of /proc/interrupts.