Re: More questions on PCMCIA internals with focus on MIPS....

On Sat, Sep 27, 2003 at 01:01:05PM -0400, Steven J. Hill wrote:
> 
>   1) I realize that PCMCIA is very x86-centric, but for other
>      architectures like MIPS, we have a larger I/O port space.

The PCMCIA bus is defined to have a 16-bit IO space, and all PCMCIA
and CardBus bridges only support 16-bit IO addresses, with direct
pass-through of PCI bus addresses to PCMCIA bus addresses.  So, I know
of no PCMCIA hardware that supports wider IO addresses.

>   2) I have questions about resource probing with regards to the
>      I/O memory. If I try and use the following in my 'config.opts'
>      file, PCMCIA devices inserted will not work;
> 
>         include port 0x00001000-0x0000ffff
>         include memory 0x18000000-0x1bffffff
> 
>      However, if I do it this way:
> 
>         include port 0x00001000-0x0000ffff
>         exclude memory 0x18001000-0x18400fff
>         include memory 0x18410000-0x187fffff
>         exclude memory 0x18800000-0x193fffff
>         include memory 0x19400000-0x1bbfffff
>         exclude memory 0x1bc00000-0x1bc00fff
>         include memory 0x1bc10000-0x1b2001ff
>         exclude memory 0x1bc20200-0x1bc202ff
>         include memory 0x1bc30000-0x1bffffff
> 
>      Things will work just fine. It also seems that when I
>      specify an 'include memory' directive that the starting
>      address has to be aligned on a 64KB boundary, otherwise
>      that address range is ignored. Why is this?

I'm not sure I can explain that.  What messages do you get with the
first set of directives?  Regarding the alignment issue, yes, that
should be documented and appropriate errors generated; I think it is
only an 8K alignment requirement.

>   3) The final item has to do with the same above configuration.
>      It should be obvious that the size of my PCI memory space
>      is only 64MB total in size. If I attempt to insert a compact
>      flash card that is 64MB in size, the board will hang. I have
>      not gone deep into the code yet, but should not the PCMCIA
>      code recognize that it will be impossible to map the card
>      into the memory space or is it being naughty and going outside
>      the memory address space?

Compact flash cards emulate IDE devices and are not memory mapped.
All cards have the same resource requirements (just space for a few IO
registers).  So, the 64 MB issue is a red herring.  Do any compact
flash cards work?

-- Dave


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