[U-Boot] [PATCH] powerpc: do not fixup NULL ptrs

Andre Schwarz andre.schwarz at matrix-vision.de
Thu Nov 4 17:53:30 CET 2010


Jocke,
>> ok - works for me, i.e. no quad-nop needed anymore.
>>      
> Does both your boards work now?
>    

MPC8343 @ 400MHz never had any issues - it's still working with your 
patch applied.

MPC8377 works fine up to 533MHz ... 600MHz+ still hangs.

Looks like there are more sync missing.

>>> I am guessing it takes a while for the stw r4, LBLAWAR1(r3)
>>> to hit the HW so one must wait for it, not sure what is
>>> best though, sync or isync?
>>>
>>>        
>> If it is a timing issue why should have the nops influenced this ?
>> I still wonder if this is the real problem and whether we might need
>> more (i)syncs elsewhere ...
>>      
> You can try replacing the isync with 4 nops. That works
> for me. moving the 4 nops after the blr doesn't work.
>
> I think it worked earlier by chance but the removal of
> the flags changed timing, probably a cache line crossing
> at the wrong place.
>    

"works by chance" is probably not what we want.

Anyway - good catch. Thanks again.


Cheers,
André

MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler
Registergericht: Amtsgericht Stuttgart, HRB 271090
Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner


More information about the U-Boot mailing list