Subject: Re: AS1200 stray IRQ messages
To: NetBSD/alpha Discussion List <port-alpha@NetBSD.ORG>
From: David Hopper <>
List: port-alpha
Date: 06/17/2004 14:31:18
On Jun 17, 2004, at 2:02 PM, Greg A. Woods wrote:

> [ On Thursday, June 17, 2004 at 22:09:35 (+0200), Manuel Bouyer wrote: 
> ]
>> Subject: Re: AS1200 stray IRQ messages
>> May be because the associated driver didn't claim the interrupt (e.g. 
>> the
>> kernel gets an IRQ 7 and the lpt driver says "it's not for me, I'm not
>> waiting for an interrupt)
> Which seems to show that there's a design flaw or bug of some sort in
> the lpt driver.
> IIUC the lpt hardware can and will generate asynchronous interrupts and
> the driver should be prepared to handle them.
> There's a similar bug on the sparc -- I recently crashed my SS20 when
> changing the state of a printer that was plugged into the system
> parallel port.

Googling for this reveals that stray irq 7 is a common occurrence on 
FreeBSD / Alpha as well, but merely an annoyance.  I'm a tad more 
concerned with the stray irq 16 (tlp0 w/ kernels <= 1.6ZK) and stray 
irq 12 (isp0 w/ kernel = 2.0F) messages I get.

At the end of the day, though, these strays could only have affected 
this production server in extremely subtle ways, if at all (I've had 
uptime of a fistful of months in spite of them).

> 						Greg A. Woods