Fedora Linux Support Community & Resources Center
Old 10th February 2012, 06:02 PM
Don3 Offline
Registered User
Join Date: Aug 2009
Posts: 30
How to restart hung USB system?

I have Fedora 14 32-bit installed on a HP EliteBook 8540w (kernel version2.6.35.12-90.fc14.i686.PAE). I know F14 is EOL, but I think I have a generic question.

Currently, the entire USB system seems to be hung. Connecting and disconnecting devices on USB 2 or 3 ports produce no message in /var/log/messages. All (external) devices are currently disconnected, but there were several devices connected when the problem started (mouse, keyboard, serial port, USB flash drive, USB disc drive), and I had just finished writing a file to the USB 3 flash drive and removing it prior to the problem starting. "lsusb" and "cat /proc/bus/usb/devices" hang, as do "modprobe -r usb_storage" or similar commands. Here is a subset of "lsmod" output:

# lsmod | grep -e 'hc[id]' -e usb
usblp                   8799  0 
xhci_hcd               80405  0 
usb_storage            35831  0 
btusb                  12522  3 
bluetooth              73233  11 rfcomm,sco,bnep,l2cap,btusb
sdhci_pci               6278  0 
sdhci                  15773  1 sdhci_pci
firewire_ohci          18005  0 
mmc_core               53242  1 sdhci
firewire_core          37917  1 firewire_ohci
Interestingly, looking at the source seems to indicate that it's trying to unload xhci_hcd and usb_storage (probably because I tried to remove them):

4# grep -e 'hc[id]' -e usb /proc/modules 
usblp 8799 0 - Live 0xf7bfc000
xhci_hcd 80405 0 - Unloading 0xf7bb1000
usb_storage 35831 0 - Unloading 0xf7cb5000
btusb 12522 3 - Live 0xf895a000
bluetooth 73233 11 rfcomm,sco,bnep,l2cap,btusb, Live 0xf86d2000
sdhci_pci 6278 0 - Live 0xf7b61000
sdhci 15773 1 sdhci_pci, Live 0xf7b51000
firewire_ohci 18005 0 - Live 0xf7b3e000
mmc_core 53242 1 sdhci, Live 0xf7b1c000
firewire_core 37917 1 firewire_ohci, Live 0xf7aea000
CPU usage is normal (nothing running away) but the loadavg is about 6 right now, due to all the hung processes:

2> ps -efl | grep '^. D '
5 D root        42     2  0  80   0 -     0 kthrea Jan26 ?        00:00:00 [khubd]
0 D me        1854  2911  0  80   0 -  1137 usb_de 08:49 pts/2    00:00:00 less /proc/bus/usb/devices
4 D root      4078  4068  0  80   0 -   553 driver 09:06 pts/1    00:00:00 modprobe -r usb_storage
0 D root      7481  5589  0  80   0 -   661 usbdev 09:35 pts/26   00:00:00 lsusb
4 D root     32111     1  0  80   0 -   553 usb_di Feb09 pts/0    00:00:00 modprobe -r xhci_hcd
I'm afraid I'm just going to have to bite the bullet and reboot this thing, since I have to get back to doing something productive with it -- but my generic question is:

Is there a way to reset the both/all USB drivers (ehci, xhci) or whatever else needs to be reset in this kind of situation? Googl'ing, I've seen suggestions to remove and re-insert the usb modules, but that just hangs in my case. And/Or, is there a way to debug this -- for example, to find why some modules can't be removed (aside from when it's obvious from lsmod that other modules are using them) ?

Reply With Quote
Old 16th February 2012, 05:03 AM
Don3 Offline
Registered User
Join Date: Aug 2009
Posts: 30
Re: How to restart hung USB system?

Well I ended up rebooting. Now 5 days on, and it's back in the same situation. I can't be sure, but I'm thinking it was triggered by unplugging a USB3 flash drive. (Yes, I did remember to un-mount it first.) I'd like to think this is a problem that would be fixed by moving up to F16, but I'm also wondering why this just started happening recently...

I'll re-post if I ever find the cause, a solution, or even an answer to the title question.
Reply With Quote

hung, restart, usb

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Is there a way to schedule a system restart? fun_4_me_now Using Fedora 14 2nd July 2010 10:06 PM
Help! How do I restart my system? JD123456 Using Fedora 6 10th January 2009 11:24 PM
How to restart sound system ? lynxus Using Fedora 2 16th June 2008 09:41 AM
system hangs on restart - HELP plz! Firewing1 Using Fedora 2 30th April 2005 07:08 PM

Current GMT-time: 04:23 (Monday, 25-09-2017)

TopSubscribe to XML RSS for all Threads in all ForumsFedoraForumDotOrg Archive

All trademarks, and forum posts in this site are property of their respective owner(s).
FedoraForum.org is privately owned and is not directly sponsored by the Fedora Project or Red Hat, Inc.

Privacy Policy | Term of Use | Posting Guidelines | Archive | Contact Us | Founding Members

Powered by vBulletin® Copyright ©2000 - 2012, vBulletin Solutions, Inc.

FedoraForum is Powered by RedHat