> > I'm facing a weird USB problem. When plugging a high-speed device in a > > friend's laptop running Gentoo, the kernel tells me "not running at top > > speed, connect to a high-speed hub.". Both ehci_hcd and ohci_hcd are > > loaded, and I tried all USB ports with no luck. > > > > The weirdest part is that if I reboot under Debian with the same kernel > > binary (both kernel image and modules), everything work fine. This is > > clearly a distribution specific issue. Could anyone tell me where I > > should investigate ? > > A good place to start is to make sure that CONFIG_USB_DEBUG is on, and > then look at (or post) the dmesg log. > > It's possible that some apparently unrelated program is preventing > ehci-hcd from driving the device. Len Brown recently posted a similar > problem on linux-usb-devel, but in his case it was two different sets of > config options for the same kernel source -- one of them worked and the > other didn't, for no obvious reason.
Thanks for your advices. I enabled CONFIG_USB_DEBUG, but the log messages were helpless. After further unsuccessful investigation, I found out that Debian loads the ehci_hcd and ohci_hcd modules in PCI bus order, which is ohci followed by ehci, while I was loading ehci_hcd first in Gentoo. Reversing the load order fixed the problem. It seems like broken hardware behaviour to me. The laptop behaves very stangely : when ACPI is enabled, the internal ps/2 keyboard is dead until ohci_hcd is loaded (the module can be unloaded after, the keyboard stays alive). For reference, I'm talking about an Acer Aspire 1674. Laurent Pinchart ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
