[FS#471] BT Home Hub 5 xrx200 SMP "rcu_sched self-detected stall on CPU" panic and freeze

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Mauro Mozzarelli (ezplanet) 

Attached to Project - LEDE Project
Summary - BT Home Hub 5 xrx200 SMP "rcu_sched self-detected stall on CPU" panic and freeze
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - Supply the following if possible:
 - Device problem occurs on BT Home Hub 5 (occuring on 2 routers)
 - Software versions of LEDE release, packages, etc. r3266, r3285, r3289, r3292, r3293
 - Steps to reproduce

Use the router normally, the freeze can happen in a few minutes or after several hours.
This happens on two routers: one is configured as a simple WiFi repeater, only one Ethernet connected, most services (dnsmasq, dhcp, dsl) are disabled.
The second router has DSL network + LAN + WiFi + RED Ethernet to additional WAN, openvpn, dhcp, dnsmasq, etc.
Although the configuration is very different, both freeze and it is difficult to determine under which circumstances.

Please see attached serial console log of one of the crashes.

I reverted back to r3220 which is the latest I saved without SMP and both routers have become stable again.

I had these routers running stable for several days before the SMP upgrade.
I hope that this can be fixed because with SMP enabled these routers are really fast, with SMP I get much higher throughput on openvpn encrypted tunnels.

   

 

One or more files have been attached.

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=471