[U-Boot] __fsl_ddr_set_lawbar: ERROR (ctrl #0, intrlv=0)

[Kumar Gala <galak@kernel.crashing.org>]

On Jul 26, 2011, at 4:23 AM, Wolfgang Denk wrote:

> Dear Kumar Gala,
> 
> In message <FC7A4DAE-B05C-49F3-9201-1B5BB559FF47@kernel.crashing.org> you wrote:
>> 
>> Do you know if this board has any real reset on a FPGA or CPLD or
>> something like that.
> 
> There is no such faeature on that board, nor on any of a number of
> other 85xx boards I have access to.
> 
>> The problem on the 8555/8541 is the reset you are trigger is just a core
>> reset and not one of the full SoC.  If there is a board level means I
>> would suggest trying to utilize it instead.  If not this might be
>> painful & problematic as you'll have to slowly make sure we are
>> 'resetting' each SoC block properly.
> 
> Is this also the cause why the Linux reboot ommand does not work?

Probably.

> If so, I wonder what has changed, because this used to be working in
> older versions of the kernel? I did not attampt a full git bisect,
> but from some old images I still found it appears it must have been
> broken between 2.6.16 ("reboot" in Linux works fine) and 2.6.27
> ("reboot" does not work any more) - so probably this was part of the
> arch/ppc => arch/powerpc rework.

Possible, its a pretty fragile reset solution so one (or a thousand) of a million things could be the issue.

> Is there any specific reason we don't use the good old approach of
> triggering an unhandled machine check exception?

Hmm, when did we do that?  I've got no issues with it if it causes HRESET_REQ to be signaled on the older devices.  On MPC8548 and greater we provided a means for software to causes HRESET_REQ to be asserted.  So if an unhandled mcheck will do this sounds good to me.

- k