cafe_ccic smbus issues

Mitch Bradley wmb at
Mon Apr 30 12:47:38 EDT 2007

Jonathan Corbet wrote:
> Andres Salomon <dilinger at> wrote:
>> The question is now, why wouldn't we be seeing interrupts?
> A good question.  
> Anyway...possible reasons for not getting interrupts:
>  - Something changed in the pre-b3 board such that the interrupt line
>    from the camera controller no longer reaches the CPU.  Seems
>    unlikely.

Actually, this is exactly what happened.  The CaFe INT pin was routed to 
a different GPIO on the 5536 in order to make room for a new INT from 
the LX chip itself.

We found and fixed this yesterday.

>  - Something changed in the Cafe startup dance with the result that
>    interrupts are no longer being enabled in the controller.  That
>    ritual has changed before...have there been Cafe changes this time
>    around? 
>  - The interrupt line is being masked in the CPU somehow.  Are there any
>    "nobody cared!" messages in the logs?  What else is sharing the
>    camera interrupt line on this board?
>  - This board has the faster processor, right?  It's possible that there
>    is a timing-related issue somewhere - the controller needs a delay
>    that wasn't required before.
> jon

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