Re: siisata at cardbus

[David Laight <david%l8s.co.uk@localhost>]

On Sat, Dec 13, 2008 at 02:58:07PM +0100, Manuel Bouyer wrote:
> > > 
> > > So how can your cardbus sii adapter work with 64bits BAR, if the 
> > > underlying
> > > hardware doesn't support it ?
> > 
> > The initial values of high of BAR0/BAR1(PCI config 0x14/0x1c) is 0.  We
> > set only low of BAR0/BAR1(0x10/0x18).  Maybe it is OK.
> 
> OK, but I can't see why the hardware maker would have used 64bit BARS here
> if it can't work on cardbus. So I guess it's supported by cardbus
> (but I didn't check the specs), and if so it's better to add support for this
> to the cardbus framework.

Given that you can have a normal PCI bus behind a cardbus card.
(Hot-plugging one is likely to fail because the BIOS won't have allowed
anywhere near enough bus numbers for the empty cardbus slot.)

I suspect this is much the same as having a 64-bit capable card behind
any 32bit PCI-PCI bridge (or possibly just in a 32bit slot).

        David

-- 
David Laight: david%l8s.co.uk@localhost