/dev/rtc Device or resource busy

Bug #59596 reported by DrSpirograph on 2006-09-09
Affects Status Importance Assigned to Milestone
linux (Ubuntu)

Bug Description

Binary package hint: linux-image-686

I am unable to use /dev/rtc at all.
This is proving to be very problematic for running vmware.

I've looked around on google and no one seems to have come up with a solution to this problem.

If I try to read from /dev/rtc, even as root, I get
opening `/dev/rtc': Device or resource busy

I've checked if there are any other processes holding the resource with fuser, but nothing is shown:

root@serenity:~# fuser -av /dev/rtc

                     USER PID ACCESS COMMAND

I'm seeing this occur straight after boot up, there seems to be no way to access the real time clock.

I am using Dapper 6.06
My CPU is Intel(R) Celeron(R) M processor 1.60GHz
uname -a : Linux serenity 2.6.15-26-686 #1 SMP PREEMPT Thu Aug 3 03:13:28 UTC 2006 i686 GNU/Linux

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering is this still an issue for you? Can you try with latest updates or the latest Ubuntu release? Thanks in advance.

Changed in linux-source-2.6.15:
status: New → Incomplete

I don't know if they above guy still has this bug, but *I* still have it in Ubuntu Gutsy running 2.6.22-14 ... has this been fixed? It really is a problem for VMWare as it can't do anything with serial ports on a timely basis either.

I have the same problem:
- Time is lagging, clock misses about an hour in a day
- /dev/rtc busy when opening, even as root

Problem started a couple of days ago. I just did "apt-get upgrade", but I still can't read /dev/rtc.

Ubuntu 7.10 Gutsy, Linux ... 2.6.22-14-generic #1 SMP Tue Feb 12 02:46:46 UTC 2008 x86_64 GNU/Linux

~$ cat /dev/rtc
cat: /dev/rtc: Device or resource busy
~$ sudo cat /dev/rtc
cat: /dev/rtc: Device or resource busy
~$ sudo fuser -av /dev/rtc
                     USER PID ACCESS COMMAND

Sebastian's questions were answerred in two comments - it's still a problem.

Changed in linux-source-2.6.15:
status: Incomplete → Confirmed

In duplicate #134518, Lincoln Stein says: "has nothing to do with the kernel. It has to do with Timidity opening the snd_rtctimer module. Now I just need to figure out how to run timidity without disabling /dev/rtc."

Stopping timidity seems to fix the busy problem.

~$ sudo cat /dev/rtc
cat: /dev/rtc: Device or resource busy
~$ sudo /etc/init.d/timidity stop
 * Stopping TiMidity++ ALSA midi emulation...
~$ sudo cat /dev/rtc
cat: /dev/rtc: Invalid argument

Beginning with the Hardy Heron 8.04 development cycle, all open Ubuntu kernel bugs need to be reported against the "linux" kernel package. We are automatically migrating this linux-source-2.6.15 kernel bug to the new "linux" package. We appreciate your patience and understanding as we make this transition. Also, if you would be interested in testing the upcoming Intrepid Ibex 8.10 release, it is available at http://www.ubuntu.com/testing . Please let us know your results. Thanks!

The Ubuntu Kernel Team is planning to move to the 2.6.27 kernel for the upcoming Intrepid Ibex 8.10 release. As a result, the kernel team would appreciate it if you could please test this newer 2.6.27 Ubuntu kernel. There are one of two ways you should be able to test:

1) If you are comfortable installing packages on your own, the linux-image-2.6.27-* package is currently available for you to install and test.


2) The upcoming Alpha5 for Intrepid Ibex 8.10 will contain this newer 2.6.27 Ubuntu kernel. Alpha5 is set to be released Thursday Sept 4. Please watch http://www.ubuntu.com/testing for Alpha5 to be announced. You should then be able to test via a LiveCD.

Please let us know immediately if this newer 2.6.27 kernel resolves the bug reported here or if the issue remains. More importantly, please open a new bug report for each new bug/regression introduced by the 2.6.27 kernel and tag the bug report with 'linux-2.6.27'. Also, please specifically note if the issue does or does not appear in the 2.6.26 kernel. Thanks again, we really appreicate your help and feedback.

Changed in linux (Ubuntu):
status: Confirmed → Invalid
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