On 2/26/07, Alan Stern <[EMAIL PROTECTED]> wrote:
> On Mon, 26 Feb 2007, Jon Smirl wrote:
>
> > My instability seems to come from a race between EHCI and UHCI. I have
> > one EHCI and four UHCI host controllers (ICH5).
> >
> > I usually get this at boot:
> > bus 1 UHCI-A
> > bus 2 UHCI-B
> > bus 3 UHCI-C
> > bus 4 UHCI-D
> > bus 5 EHCI
> >
> > But occasionally I get this. I don't see a pattern, it feels like a race.
> > bus 1 EHCI
> > bus 2 UHCI-A
> > bus 3 UHCI-B
> > bus 4 UHCI-C
> > bus 5 UHCI-D
> >
> > My USB is all loading as modules. I don't see any option to control
> > parallel PCI probing in 2.6.20.
>
> The option is called CONFIG_PCI_MULTITHREAD_PROBE, and it is marked BROKEN
> in 2.6.20.  So it's probably not the reason.  More likely you're just up
> against an ordinary race.  At some point in the boot process udev starts
> up, it spawns lots of modprobe tasks all running at the same time, and any
> one of them could end up beating the others.
>
> You could remove this indeterminism by explicitly loading ehci-hcd and
> uhci-hcd (that is the preferred order) in a system start-up script before
> udev.  In FC6, for example, the modules are loaded from an initramfs
> script.

In think the usb modules on initramfs with Unbuntu, but they must not
be proloading them with a script. But doesn't loading from a script
defeat the mechanism of only loading what modules you need?

Another way to control this would be to put all of the USB Host IDs
into a single module (usbcore), and then that module would load in
ehci, uhci, etc.

-- 
Jon Smirl
[EMAIL PROTECTED]

-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
linux-usb-devel@lists.sourceforge.net
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel

Reply via email to