Re: Linux 2.4.5-ac7

Pete Zaitcev (zaitcev@redhat.com)
Sun, 3 Jun 2001 16:51:42 -0400


> AC> 2.4.5-ac7
> AC> o Make USB require PCI (me)

> How about people from StrongArm sa11x0 port, who have USB host controller
> (in sa1111 companion chip) but do not have PCI?
> Probably there are more such embedded architectures with USB controllers,
> but not PCI bus.

There is nothing that would bind USB to PCI architecturally.
OHCI and UHCI are PCI based, but that's just a matter of
implementation. I think that Alan was unwise at this point.

I know that some small Motorola parts (relatives of 860, perhaps)
do have USB controllers, but I have no idea if PCI is involved.

> How about ISA USB host controllers?

Those, unfortunately, do not exist. I was shopping for one
in vain for a long time. One formiddable difficulty is that
USB bandwidth is larger than ISA, so the only feasible way
to make a HC is to have all TD's in its onboard memory,
as in VGA.

In other follow-up Alan argued in favor of CONFIG_PCI for
a PCI-less machine. It may be a reasonable approach, for
instance JavaStation-1 has no PCI but requires CONFIG_PCI.
It adds a little of useless bloat, that I considered a
necessary evil in the abovementioned case.

-- Pete
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