Re: Linux 3.8-rc1 - another regression on USB :-(

[Woody Suwalski]

Alan Stern wrote:
> On Tue, 15 Jan 2013, Woody Suwalski wrote:
>
> > > Another important change is that the EHCI driver is now split into two
> > > modules.  That can slow down loading and affect the timing.
> > >
> > > Alan Stern
> > My testcase is a live initramfs + squash root.
> > The boot logic is as stable as can be - unchanged since 2.6.2x kernels.
> > And it was working fine till 3.8-rc1.
> >
> > The modules are insmoded in a fixed order:
> > usb-common, usbcore, xhci-hcd, ehci-hcd, uhci-hcd, ohci-hcd, usbhid,
> > usb_storage,...
> But apparently you don't insmod ehci-pci.  That could cause problems,
> if your EHCI controller is PCI-based.
>
> > If all USB is built as modules - I get read errors from USB drives when
> > accessing squash image, boot fails.
> What read errors?  What is the cause of these errors?
>
> > If usb-common and usbcore are built in, system seems to crawl with a
> > very slow USB, but boots. That could be caused by timing between hcd
> > modules.
> Do have a dmesg log with timestamps so we can see where things go slow?
> I suggest enabling CONFIG_PRINTK_TIME and CONFIG_USB_DEBUG.  You might
> even want CONFIG_USB_STORAGE_DEBUG, although that often logs too much
> information.
>
> > If usb-common, usbcore and ehci-hcd are built-in, all works OK like
> > "before 3.8".
> What about ehci-pci?
Alan, it took me 2 times re-reading the email to notice...
You were talking about ehci-pci, not ehci-hcd... Old assumptions die hard...
Yep, that was it.
Catch22 - I would have noticed new dependency if I could boot, but to 
boot I have had needed to notice the new dependency...

Case solved 8-)

Thanks, Woody

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