lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <Pine.LNX.4.44L0.1511231045410.1831-100000@iolanthe.rowland.org>
Date:	Mon, 23 Nov 2015 10:52:42 -0500 (EST)
From:	Alan Stern <stern@...land.harvard.edu>
To:	Daniel J Blueman <daniel@...ra.org>
cc:	USB list <linux-usb@...r.kernel.org>,
	Linux Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [4.3] kworker busy in pm_runtime_work

On Sun, 22 Nov 2015, Daniel J Blueman wrote:

> On 16 November 2015 at 23:22, Alan Stern <stern@...land.harvard.edu> wrote:
> > On Mon, 16 Nov 2015, Daniel J Blueman wrote:
> >
> >> Tuning USB suspend [1] in 4.3 on a Dell XPS 15 9553 (Skylake), I see a
> >> kworker thread spinning in rpm_suspend [2].
> >>
> >> What is the most useful debug to get here beyond the immediate [3]?
> >
> > You can try doing:
> >
> >         echo 'module usbcore =p' >/sys/kernel/debug/dynamic_debug/control
> 
> kworker and ksoftirqd spinning occurs when I echo 'auto' to all the
> USB control entries. Using Alan's excellent tip, we see this being
> logged repeatedly at a high rate:
> [  353.245180] usb usb1-port4: status 0107 change 0000
> [  353.245194] usb usb1-port12: status 0507 change 0000
> [  353.245202] hub 1-0:1.0: state 7 ports 16 chg 0000 evt 0000
> [  353.245203] hub 1-0:1.0: hub_suspend
> [  353.245205] usb usb1: bus auto-suspend, wakeup 1
> [  353.245206] usb usb1: bus suspend fail, err -16
> [  353.245207] hub 1-0:1.0: hub_resume
> ...
> 
> So, EBUSY. Both the webcam is not open, and the bluetooth interface
> [1] is rfkill'd; the situation occurs even if I unload all related
> modules.
> 
> What further debug would be useful?
> 
> Thanks!
>   Daniel
> 
> -- [1]
> 
> Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
> Bus 001 Device 002: ID 0a5c:6410 Broadcom Corp.
> Bus 001 Device 003: ID 1bcf:2b95 Sunplus Innovation Technology Inc.
> Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Since bus 1 uses an xHCI controller, you should do:

	echo 'module xhci-hcd =p' >/sys/kernel/debug/dynamic_debug/control

I'm reasonably sure this will end up printing "suspend failed 
because a port is resuming", since that's the only place where 
xhci_bus_suspend() fails with -EBUSY, but you should try it to confirm 
this.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ