Re: Logs being spammed with "Unable to enumerate USB device"

Previous thread: [PATCH 0/4] FHCI USB Host support patches by Anton Vorontsov on Tuesday, September 23, 2008 - 5:02 pm. (14 messages)

Next thread: Re: Interrupt handler latency and Interrupt handling issues by Robert Hancock on Tuesday, September 23, 2008 - 5:17 pm. (1 message)
From: Robert Hancock
Date: Tuesday, September 23, 2008 - 5:14 pm

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.
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From: Larry Finger
Date: Tuesday, September 23, 2008 - 6:00 pm

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.

Larry


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From: Larry Finger
Date: Tuesday, September 30, 2008 - 4:38 pm

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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Previous thread: [PATCH 0/4] FHCI USB Host support patches by Anton Vorontsov on Tuesday, September 23, 2008 - 5:02 pm. (14 messages)

Next thread: Re: Interrupt handler latency and Interrupt handling issues by Robert Hancock on Tuesday, September 23, 2008 - 5:17 pm. (1 message)