Debugging System Lockup

[Anthony Jenkins]

On 07/01/16 13:49, Pete Wright wrote:

> On 07/01/2016 03:53, Gary Jennejohn wrote:
>> On Thu, 30 Jun 2016 16:02:30 -0700
>> Pete Wright <pete at nomadlogic.org> wrote:
>>
>>> Hi All,
>>> 	I've been working with mmacy on testing the new i915kms support on
>>> skylake.  I've got a stubborn bug where I am able to trigger a hard-lock
>>> of my system requiring a manual power-off/power-on to get it back in
>>> working order.  Unfortunately, I have not been able to get any debugging
>>> information out of this system when this happens - no core, backtrace in
>>> dmesg buffer, etc.
>>>
>>> I was hoping someone on this list has had experience in debugging
>>> situations like this and could offer some tips for trying to get useful
>>> info out of this crash.  I was going to configure my system to use
>>> dcons(4) - but this system does not have a fireware device, so that
>>> seems to rule out that avenue.  So any input would be really appreciated!
>>>
>> Serial console?  Should even work well enough using a FTDI adapter.
> Unfortunately the system I am debugging only has USB - I investigated
> using some of the advanced Intel SOL functionality on the system (it's a
> Lenovo M900 Tiny micro-computer) but it requires windows to work.
>
> I did test using a usb->db9 serial adapter which was then connected to
> may laptop (which also had a usb->db9 serial adapter) but that was
> unsuccessful.
>
> cheers,
> -pete
I haven't actually tried this yet, but I recently purchased a PCIe
serial port card from Amazon in hopes of tackling this exact problem
with my serial-less laptop.  I'll have to run it without the case, but
(if it works) it's better than nothing.

SIIG 2-Port Serial Mini PCIe with Power Board JJ-E20211-S1
https://www.amazon.com/gp/product/B008HSKJBM

Anthony