Re: Modem gone after suspend/resume

[Dan Williams <dcbw redhat com>]

On Fri, 2010-08-06 at 19:21 +0400, Andrey Borzenkov wrote:
> On Friday 06 of August 2010 18:30:48 Torsten Spindler wrote:
> > Hello,
> >
> 
> > a 3G modem is no longer recognized by modem-manager when the
> system
> > resumes. It seems the USB identification changes upon resume,
> from
> > usb6/6-1 to usb6/6-2. This might be caused by udev rules?
> >
> 
> 
> Nope, it did not change. Device usb6/6-2 existed also before
> suspend:
> 
> [    2.444051] usb 6-2: new full speed USB device using
> uhci_hcd and address 3
> [    2.636033] usb 6-2: configuration #1 chosen
> from 1 choice
> 
> There is not enough information to know what it is, but
> I guess it is (built-in?) smart card reader, based on
> 
> [ 4251.276912]
> usb 6-2: usbfs: process 1360 (pcscd) did not claim interface 0 before
> use
> 
> Compare lsusb -v output before and after resume.
> 
> As for your
> modem - it seems to have dropped off after resume:
> 
> [ 4251.624038] usb
> 6-1: new full speed USB device using uhci_hcd and address 4
> [
> 4251.744422] usb 6-1: device descriptor read/64, error -71
> [
> 4251.968059] usb 6-1: device descriptor read/64, error -71
> [
> 4252.184088] usb 6-1: new full speed USB device using uhci_hcd and
> address 5
> [ 4252.304068] usb 6-1: device descriptor read/64, error
> -71
> [ 4252.528099] usb 6-1: device descriptor read/64, error -71
> [
> 4252.744095] usb 6-1: new full speed USB device using uhci_hcd and
> address 6
> [ 4253.160115] usb 6-1: device not accepting address 6,
> error -71
> [ 4253.272083] usb 6-1: new full speed USB device using
> uhci_hcd and address 7
> [ 4253.688067] usb 6-1: device not accepting
> address 7, error -71
> [ 4253.688104] hub 6-0:1.0: unable to enumerate
> USB device on port 1
> 
> I would start with checking that device alone
> (without any application) can survive suspend/resume cycle. Stop NM/MM
> to make sure nothing attempts to attach to device; plug in modem;
> verify that it is available using lsusb; now suspend/resume and check
> whether modem is still available. If not - this is kernel problem and
> NM cannot do anything about it.

If the modem *does* come back after resume and provides serial ports,
but MM doesn't notice those ports, then it's likely a driver/udev
problem in the kernel.

But like Andrey has diagnosed, it looks like the modem simply doesn't
come back after resume, likely because it's firmware doesn't handle
resume well, or there's a kernel bug with USB bus re-enumeration on
resume.

Dan

> 
> > I've collected some logs here on
> Launchpad:
> > dmesg after resume:
> >
> http://launchpadlibrarian.net/53157289/dmesg
> > find in the sys
> directory after resume:
> >
> http://launchpadlibrarian.net/53157295/find
> > debug output for
> modemmanager:
> > http://launchpadlibrarian.net/53157338/mm.log
> > 
> > Any
> chance to get modem-manager/networkmanager to rescan the device
> > tree
> to find the modem again?
> > 
> > Torsten
> > 
> > 
> >
> _______________________________________________
> > networkmanager-list
> mailing list
> > networkmanager-list gnome org
> >
> http://mail.gnome.org/mailman/listinfo/networkmanager-list
> 
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