[U-Boot] [PATCH PPC_4xx V3] Print simple row of dots instead of spinning wheel

[Jean-Christophe PLAGNIOL-VILLARD]

On 13:06 Fri 31 Oct     , Stefan Roese wrote:
> Hi Wolfgang,
> 
> On Friday 31 October 2008, Wolfgang Denk wrote:
> > > > It is my understanding that a rework of this code is under way  which
> > > > will  avoid  the  long delay for the standard boot sequence (and only
> > > > need it for board bringup or  intentional  recalibration).
> > >
> > > Are you talking about storing the optimized autocalibration values in
> > > FLASH, as discussed on IRC some time ago? I don't know if somebody is
> > > working on
> >
> > Yes. I see this as a mandatory requirement. The additional delays are
> > not aceptable.
> 
> I just want to raise some concerns about this approach on boards with DIMM 
> modules. Here it will be hard to determine if a new DIMM module is installed. 
> Even a module from the same manufacturer and type (size, width etc, all the 
> same) will need a new autocalibration. This is probably hard to detect.
> 
> Just my $0.02.
As discuss on IRC with Stefan

we can use the EEPROM present on the DIMM to identify two Modules

as point to this link as example
http://www.micron.com/products/spddetail.aspx?part=MT16HTF12864HY-667F1

we have the following interested informations stored

Byte	Byte Description
Number
64-71	MANUFACTURERS JEDEC ID CODE
73-90	MODULE PART NUMBER
95-98	MODULE SERIAL NUMBER

we can check this 3 fields to be sure if it's a new modules is installed and
so re-do the calibration

Why the 3 fields?
By experience
I've seen 2 Manufacturs use the same Serial Number for 2 differents product
and I've also seen a Manufactur using the same Serial Number for 2 differents
Part number

Best Regards,
J.