Re: pm_op(): usb_dev_suspend+0x0/0x10 returns -2 on USB device 8087:0020

["Ákos Maróy" <akos@maroy.hu>]

Alan,

> You can get more information if you enable CONFIG_USB_DEBUG in your
> kernel configuration.  The most likely explanation is that the suspend
> failed because one of the ports on that root hub issued a wakeup
> request.

I tried, and this is what I seem to be getting now:


Feb 24 23:28:52 tonkachi kernel: [  348.733460] PM: Syncing filesystems ...
Feb 24 23:28:52 tonkachi kernel: [  348.903106] done.
Feb 24 23:28:52 tonkachi kernel: [  348.903123] Freezing user space
processes ... (elapsed 0.00 seconds) done.
Feb 24 23:28:52 tonkachi kernel: [  348.903808] Freezing remaining
freezable tasks ... (elapsed 0.00 seconds) done.
Feb 24 23:28:52 tonkachi kernel: [  348.903952] Suspending console(s)
(use no_console_suspend to debug)
Feb 24 23:28:52 tonkachi kernel: [  348.985903] xhci_hcd 0000:02:00.0:
WARN: short transfer on control ep
Feb 24 23:28:52 tonkachi kernel: [  348.987274] PM: resume devices took
0.060 seconds
Feb 24 23:28:52 tonkachi kernel: [  348.987371] Restarting tasks ...
Feb 24 23:28:52 tonkachi kernel: [  348.988165] done.


though I don't see the pm_op() error log anymore..

would this make sense?

actually, the whole USB susbsystem seems to be very fragile - I plug in
a USB device, and the whole system freezes for about 5 seconds or more.
then the device is registered (for example, a mouse). but I unplug and
re-plug, and the device doesn't work anymore...

or I plug in an external USB DVD drive - but if I unplug it, it is still
listed in lsusb..


Akos