Messages in this thread | | | Date | Tue, 30 Sep 2008 18:38:16 -0500 | From | Larry Finger <> | Subject | Re: Logs being spammed with "Unable to enumerate USB device" |
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Larry Finger wrote: > Robert Hancock wrote: >> Is this just occurring during bootup? I think this is normal if the EHCI >> driver is loaded after UHCI or OHCI because it causes the device to be >> switched away from the other controller that's trying to enumerate it, >> at least momentarily. > > It sometimes happens at bootup, but at other times I will get hundreds > of them in a row in the logs. I have put in some debugging where the > message is triggered, but have not seen any of the flood-type since.
I now have more information. The if statement that triggers the message is as follows:
if (hub->hdev->parent || !hcd->driver->port_handed_over || !(hcd->driver->port_handed_over)(hcd, port1))
For all the messages that I have captured, the first condition (hub->hdev->parent) is always true.
For the isolated message that occurs at bootup, the second condition (!hcd->driver->port_handed_over) is true and the third is false.
When the message storm occurs, the second condition is false, i.e. hcd->driver->port_handed_over is not zero, but !(hcd->driver->port_handed_over)(hcd, port1) is true.
As before, I am willing to test any patches. As the message storm is rare, it will be difficult to show that a patch fixes the problem.
Larry
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