Experimental Physics and
Industrial Control System

Matt Rippa <[email protected]> · Fri, 21 Mar 2014 11:13:59 -1000

Hi Andrew,

On 03/21/2014 10:37 AM, Andrew Johnson wrote:
> Hi Matt,
> 
> On 03/21/2014 02:21 PM, Matt Rippa wrote:
>> I have an MVME6100 with Epics 3.14.12.2 running vxWorks 5.5.
>> Sometimes when testing changes to a new vxworks kernel or just
>> an update to a new epics module, my shell stops hard, and Ctrl-x
>> doesn't work. Power cycling is my best friend in that case, but
>> is it my only option?
> 
> Does hitting the VME Chassis reset button rescue you from those hang-ups?

Yes, most times this works. But not always.

>> Can a modified reboot handler help with any of these occurrences?
> 
> I think by the time the CPU has frozen it's going to be too late, unless
> a VMEbus reset does work and you can arrange for some way to trigger it
> remotely.

> Here at the APS we connect to most of our VME console ports through a
> locally-designed adapter board which monitors the serial line for a
> particular key sequence (usually Ctrl+Y three times in a row). When it
> sees that, it pulses the VMEbus reset line, which is usually enough to
> restart most frozen systems. If we're unlucky we might have to send
> someone to walk out to the crate to power-cycle it, but that's fairly rare.

That's what I thought. My cases are fairly rare too.

The adapter sounds quite useful. Would this type of design work
with the MVME-6100 board which doesn't use the VME backplane for
serial communications? In my case though, it seems like a
tougher sell than adding a network bootbar.

> The other thing I would recommend is that you examine all of your
> drivers for cards that use interrupts, and make sure that they all
> register a reboot hook routine (or an epicsAtExit one) that disables the
> interrupt on the card. In my experience the main reason for systems
> freezing over a reboot is that they leave an interrupt line asserted,
> and that prevents the OS from coming back up properly.

Oh, good to know. I have a few periphery boards and will see if
this applies.

> HTH,
> 
> - Andrew
> 

Thank you,
-Matt

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System