Multiple PCI devices on the same IRQ: kernel or driver?

Donald Becker
Mon Nov 30 15:58:31 1998

On Mon, 30 Nov 1998, Mark Martin wrote:

> I recently purchased a Netgear FA310TX card and have been having the
> same problem as Erik Beck, namely my BIOS insists on putting all of my
> PCI devices on IRQ 10 and does not give me any control over the
> situation.  Consequently, whenever I try to bring the interface up, I am
> greeted with the error message
> SIOCSIFFLAGS: Resource temporarily unavailable


> There has been a fair amount of traffic on the mailing list about Erik's
> problem.  Erik indicated that he had been advised that sharing an IRQ
> under Linux was "not a good idea".

It is OK.  It works well.

> Jon Lewis suggested that the kernel
> does a poor job of IRQ sharing but suggested hacking the tulip driver. 

NOoooo.  Hack the driver that's causing the problem.
It's likely a SCSI driver.

> David ( implicated the kernel when he mentioned
> that he has no trouble sharing an IRQ and credited the development
> kernels that he runs.

No, PCI IRQ sharing has worked since 1.1.73 or so.

Donald Becker
USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771