[Soekris] CF Master/Slave issue workaround on 4801

[Stuart Henderson]

--On 22 October 2005 23:55 -0700, Phil Karn wrote:

> Does this work even if you use a CF card that isn't "buggy", like the
> Lexar?

Not exactly (unless you count always doing 'set flash=secondary', but 
then that may fail with a newer rev 4801).

> I want to be able to swap cards without regard to vendor.

Unfortunately, you can't rely on them all doing the same thing, even a 
single vendor may change supplier and start to work differently.

> What's the nature of the bug? Is it that some CF cards use a "cable
> select" feature that's buggy or non-standard?

They are all supposed to do cable select, but it's not always sampled 
at reset, just power-up. Read more about it is here:

<http://article.gmane.org/gmane.comp.hardware.soekris.technical/6510>

> I've sometimes had problems with cable select even with regular
> hard drives, so I've always avoided it when possible.

IME it hasn't been a problem with hard drives on standard PCs over the 
last few years. You've got to work with it when you use CompactFlash 
since there's no other way to indicate master/slave (e.g. in a CF-IDE 
converter, the jumper really means cableselect/secondary, regardless of 
what's actually printed on the pcb, so you have to use the appropriate 
connector if you want primary).