Best Practices - interrupt storm

[Alex Zbyslaw]

Charles Howse <chowse at charter.net> wrote:

>FreeBSD 6.1-RELEASE, cups-1.1.23.0_1, HP 1100 LaserJet
>
>I've found quite a bit of information about how to deal with:
>"Interrupt storm detected in "irq7:"; throttling interrupt source"
>
>Problem is, it's a little confusing.
> From what I've gathered, the options are:
>Use the BIOS to set the printer port to ECP,
>Use lptcontrol to set the port to polled mode,
>Use device.hints to do both
>
>IIRC, in the past, I have used lptcontrol to set polled mode, but  
>that resulted in:
>"too many stray irq7's, not logging any more"
>
>Can anyone suggest a method to make both "interrupt storm" and "too  
>many stray irq7's" go away?
>

I always set to EPP in BIOS and device.hints to 0x24 (used to compile 
into kernel pre 5.X).  (I suspect one or the other would do, and ECP 
would do instead of EPP, or 0x28 instead of 0x24).  Haven't had an 
interrupt storm or stray interrupt since.  man ppc for the flags to use 
and get into practice converting hex to binary and vice versa :-)  Never 
used lptcontrol.

--Alex