Re: Au1500 and TI PCI1510 cardbus

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Marco Braga wrote:
> 2007/3/20, Sergei Shtylyov <sshtylyov@ru.mvista.com>:

>>     What I don't understand is why use USB card on CardBus, if the Au1500
>> datasheet clearly tells us (well, at least me :-) that this is *not* 
>> going to work?

> I'll reply for my part: we need something hotswappable, and support for
> wifi. The first idea was to use cardbus, so a board was built using 
> PCI1510.
> When the system was projected, USB2.0 was not easy to find (if even 
> existed)
> and almost every wifi card was PCMCIA or Cardbus. The PCI1510 never worked,
> and it seems now that never will. So at the moment an alternative is to try
> a wifi dongle on USB. USB 1.x was too slow, but USB 2.0 seems ok for our
> application. Au1500 does not support USB2.0, so I am looking for a
> PCI/USB2.0 controlles. Does something similar exist? Does it work on 
> Au1500?

    Well, it all should be working fine in the board's own PCI slots, i.e. on 
the primary PCI bus.

> To make it short, we are NOT trying to make USB work on Cardbus, but to use
> either cardbus OR usb. :-)

>  From what you've told me cardbus on PCI (being a bridge) cannot work with
> AU1500's PCI device. So the next idea is to try an USB controller on PCI.
> Will it work? Well, I'm hoping for some fresh hand advice on this.

    Yes, this should work.

> Now Takeyoshi tells me that he's using both USB2.0 and Cardbus (not USB on
> Cardbus), so this seems interesting. I still think that USB is the best way

    From what I saw his USB is not on the primary bus, so he's taking the 
mentioned risks.

> to go, but still a working PCI to Cardbus controller can be interesting. 
> But
> I don't know how he's managed to make it work, since from what you have 
> told
> me it should not work.

    The layout of his PCI busses is not clear from lspci's dump he's cited but 
his USB is clearly in the "risk zone".

> Perhaps he's not using Cardbus devices but PCMCIA.

    It's not me -- it's written in the publicly available datasheet (spec. 
update I have just has more details :-)

WBR, Sergei