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Date:   Tue, 24 Mar 2020 09:47:40 -0400 (EDT)
From:   Alan Stern <stern@rowland.harvard.edu>
To:     Qais Yousef <qais.yousef@arm.com>
cc:     Oliver Neukum <oneukum@suse.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: lockdep warning in urb.c:363 usb_submit_urb
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On Tue, 24 Mar 2020, Qais Yousef wrote:

> I should have stuck to what I know then. I misread the documentation. Hopefully
> the attached looks better. I don't see the new debug you added emitted.

These lines:

[  158.113836] ohci_hcd:ohci_resume: ohci-platform 7ffb0000.ohci: powerup ports
[  158.139682] usbcore:hcd_bus_resume: usb usb2: usb resume
[  158.139715] ohci_hcd:ohci_rh_resume: ohci-platform 7ffb0000.ohci: resume root hub
...
[  158.219604] usbcore:hub_resume: hub 2-0:1.0: hub_resume
[  158.220482] usb usb2: runtime PM trying to activate child device usb2 but parent (7ffb0000.ohci) is not active

suggest there is a bug in the platform code.  The 7ffb0000.ohci 
platform device should already be resumed and active at this point.

Following that, this is suspicious:

[  158.482995] PM: Cannot find swap device, try swapon -a
[  158.488379] PM: Cannot get swap writer

Since there was never any device attached to the OHCI controller, this
error is not connected to the previous one.  In fact, the swap device
was plugged into the EHCI controller; it was 1-1.1.  But the log
doesn't contain anything about that device being suspended, resumed, or
disconnected.  What happened to it?

[  159.064094] OOM killer enabled.
[  159.067351] Restarting tasks ... 
[  159.068831] usbcore:hub_event: hub 2-0:1.0: state 7 ports 1 chg 0000 evt 0000
[  159.079921] usbcore:hub_event: hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000
[  159.079959] usbcore:hub_event: hub 1-0:1.0: state 7 ports 1 chg 0000 evt 0000
[  159.090776] done.
[  159.097076] usbcore:hub_resume: hub 2-0:1.0: hub_resume
[  159.102961] ------------[ cut here ]------------
[  159.107805] URB (____ptrval____) submitted while active

And why was usb2 resumed twice in a row with intervening suspend?

Alan Stern