ide-cs and interrupts

[Steven Newbury]

--- Daniel Mack <daniel at caiaq.de> wrote:

> Hi,
> 
> I seem to have a general problem in understanding how ide-cs is  
> supposed to work.
> On my i.MX31/ARM11 based board here, the PCMCIA socket is correctly  
> detected, it sees cards being inserted and can read its IDs and  
> everything. However, once I attach the ide-cs driver to an inserted  
> CompactFlash card (which has no other functions than that), I keep  
> getting "hda: lost interrupt" messages.
> 
> Thus, I traced the interrupts in question and found out that there is  
> indeed no interrupt occuring in the kernel, and in fact not even on  
> the hardware. While I'm forcing interrupts manually on the IREQ# line  
> of the card, I can get rid of the messages and make the card  
> functional, so I'm sure that it's not about the the communication in  
> general but only about this missing interrupt requests.
> 
> What confuses me is that the card - as it's set to IO mode - does not  
> drive the IREQ# line at all, however it's fully functional besides  
> that. I tried with different cards, all behave the same.
> 
> Is this an hardware issue? Or anything in the software layer I missed  
> to trace? Does the card need any more setup sequence to actually  
> generate strobes on IREQ#?
> 
> Please Cc: me in answers, I'm not subscribed to the list.
> 
> Many thanks for any hint,
Hi Daniel,
I'm pretty sure I hit the same problem when I was trying to get ide-cs to work
with MMIO on a Hitachi Microdrive via pxa270.  The card word be identified but
no interrupt would ever arrive.  If anybody has any idea why this happens I
would love to hear.  Getting this going would give a nice performance boost to
PCMCIA/CF devices since they are currently only driven with standard timings
and this would make it possible to use the card supplied IO timings.

Steve


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