Bug 911566 - Suspicious RCU usage in ar5523 driver
Summary: Suspicious RCU usage in ar5523 driver
Keywords:
Status: CLOSED INSUFFICIENT_DATA
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 19
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2013-02-15 11:29 UTC by Zoltan Boszormenyi
Modified: 2013-04-23 17:28 UTC (History)
6 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2013-04-23 17:28:09 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)
dmesg with the "suspicios RCU usage" complaint (60.74 KB, application/x-troff-man)
2013-02-15 11:29 UTC, Zoltan Boszormenyi
no flags Details

Description Zoltan Boszormenyi 2013-02-15 11:29:18 UTC
Created attachment 697701 [details]
dmesg with the "suspicios RCU usage" complaint

Description of problem:

I have installed Fedora 18 on an old IBM Thinkpad that has a Netgear WPN111 USB wifi dongle. I have read that kernel 3.8.0 contains the driver for this device and is called ar5523. I have installed the latest 3.8.0-rc7-git-3.1 from koji:
http://koji.fedoraproject.org/koji/buildinfo?buildID=386605
and all is (almost) good, this device works out of the box with the latest linux-firmware from Fedora 18 updates.

This is also a request for enhancement in Fedora 18, to be rebased to kernel 3.8.x when it's released.

However, the kernel complains about this driver with:

[  393.748199] ===============================
[  393.748207] [ INFO: suspicious RCU usage. ]
[  393.748220] 3.8.0-0.rc7.git3.1.fc19.i686.PAE #1 Tainted: G        W   
[  393.748228] -------------------------------
[  393.748238] net/mac80211/sta_info.c:216 suspicious rcu_dereference_check() usage!

Attached is the full dmesg for reference.

Version-Release number of selected component (if applicable):

kernel-PAE-3.8.0-0.rc7.git3.1.fc19.i686.rpm from the above link.

How reproducible:

Always.

Steps to Reproduce:
1. Install Fedora, with kernel 3.8.0 (unreleased at the time of writing)
2. Plug an USB wifi dongle supported by the ar5523 driver into the machine.
3. Do networking, browsing, etc.
  
Actual results:

The above complaint from the kernel. The network is alive and well, though.

Expected results:

No kernel errors cause by the ar5523 driver.

Additional info:

Comment 1 Fedora End Of Life 2013-04-03 15:44:35 UTC
This bug appears to have been reported against 'rawhide' during the Fedora 19 development cycle.
Changing version to '19'.

(As we did not run this process for some time, it could affect also pre-Fedora 19 development
cycle bugs. We are very sorry. It will help us with cleanup during Fedora 19 End Of Life. Thank you.)

More information and reason for this action is here:
https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora19

Comment 2 Justin M. Forbes 2013-04-05 18:45:35 UTC
Is this still an issue with the 3.9 kernels in F19?

Comment 3 Justin M. Forbes 2013-04-23 17:28:09 UTC
This bug is being closed with INSUFFICIENT_DATA as there has not been a
response in 2 weeks.  If you are still experiencing this issue,
please reopen and attach the relevant data from the latest kernel you are
running and any data that might have been requested previously.


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