kernel panic with pccard insert on recent 7.0 CURRENT

Garrett Cooper youshi10 at
Sun Jun 17 07:39:43 UTC 2007

Garrett Cooper wrote:
> Wilkinson, Alex wrote:
>>     0n Sat, Jun 16, 2007 at 11:56:59PM -0600, M. Warner Losh wrote:
>>     >Yes.  I'm pretty sure that's wrong.  All ISA and PC Card devices 
>> use
>>     >edge triggered interrupts.  Also, it is inefficient for level
>>     >triggered interrupts, since two interrupt sources on the same
>>     >interrupt may trigger at about the same time...
>> What is meant by "edge triggered interrupts" ?
>>  -aW
>    I'd assume 'edge triggered interrupts' mean interrupts which occur 
> on some sort of clock edge, most likely dealing with a clock base 
> required for setup, or predefined by the designers for some other reason.
> -Garrett

    If the previous email was just noise (thought it might be after the 
fact), think of "edge triggered interrupts" as something that was 
designed to occur periodically in order to meet a precondition :).

    Traditional interrupts can be asynchronous, whereas this edge 
triggered interrupts are synchronous with a clock signal of some kind 
(more like polling I think).

    Hopefully that clarifies some things...


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