Are there USB issues with 800/900 MHz iBooks/YDL 3.0?

[Tim Seufert]

On Tuesday, May 6, 2003, at 05:13  AM, Aurel Wisse wrote:

> Burnt by the OPTi controller experience in my iMac, I
> would like to be sure about the stability of the USB
> interface (hw/sw) on the newest iBooks before
> upgrading (which is going to happen in the next few
> weeks, coupled with a purchase of YDL 3.0).
>
> Are there *any* USB issues with this configuration,
> like interference of control/bulk/interrupt data
> transfers, or equivalently, mouse/printer/usb-storage?
> In other words, can you 1) move the (usb) mouse, 2)
> type on the (usb) keyboard 3) communicate with the
> external usb drive and 4) usb print at the same time
> without data corruption?

What makes you sure these things were caused by the OPTi controller?  I 
ask because it seems as though there's no way you could have tested a 
different controller on an iMac, and I'm pretty sure that I recently 
read some LKML traffic concerning serious known bugs lurking in the 
Linux USB driver stack well into the 2.4 stable series.  IIRC these 
issues are supposed to be fixed in 2.4.21-preN or something along those 
lines.

Anyways, all AGP macs use OHCI USB controllers integrated into the Key 
Largo south bridge IC, rather than a discrete PCI OHCI USB chip like 
the OPTi in your iMac.  Later AGP machines such as the iBook you're 
interested in use one USB controller per port for better total 
throughput when using high speed USB devices on both ports.  
Furthermore, iBooks and PowerBooks use a pseudo-ADB bus rather than USB 
for the internal keyboard and trackpad (there's no physical ADB bus but 
it looks like ADB to the OS).  This means you'll actually have just one 
USB device per USB bus, which may mask the bugs you experienced 
(whether hardware or software) even if they're still present.  
(Actually I take that back; I think the internal soft modem is a USB 
device now, so one bus will have two devices on it.)