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

[Donald Becker]

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

Read
  http://cesdis.gsfc.nasa.gov/linux/misc/irq-conflict.html

> 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 (david@kalifornia.com) 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					  becker@cesdis.gsfc.nasa.gov
USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
301-286-0882	     http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html