[U-Boot] [RFC PATCH 1/2 v2] nand: allow delayed initialization

[Mike Frysinger]

On Thursday, October 07, 2010 17:26:55 Mike Frysinger wrote:
> On Thursday, October 07, 2010 15:35:44 Wolfgang Denk wrote:
> > Mike Frysinger wrote:
> > > > Do you plan to post an update?
> > > 
> > > there isnt a clear indication of where to take this.  seems like we
> > > want to do this, and we want it as the default moving forward, but we
> > > want all existing boards to be unchanged.  so only reasonable way
> > > would be to invert the logic, add a define for the arch lib/board.c
> > > files, and then add that define to all existing boards.
> > 
> > I don't think we want to modify 550+ Board configurations and re-test
> > on that many boards...
> 
> it would be ~100 boards.  board_init() is only called when CONFIG_CMD_NAND
> is defined.  so it should be as simple as:
> 	sed -i \
> 	'/define[[:space:]]*CONFIG_CMD_NAND/i#define CONFIG_NAND_EARLY_INIT' \
> 	include/configs/*
> 
> > I think we should rather enable the new feature by some #define, and
> > recommend to enable this on new boards.
> 
> problem with recommendations is that people dont notice them

hmm, what about this scheme:
 - add NAND_MAYBE_EARLY_INIT to include/config_defaults.h
 - have nand_init() emit a #warning if NAND_MAYBE_EARLY_INIT is defined but 
NAND_EARLY_INIT is not
 - board porters add either "#define NAND_EARLY_INIT" or "#undef 
NAND_MAYBE_EARLY_INIT" to their board config
 - after a release or two, we set "#define NAND_EARLY_INIT" to any boards 
where their maintainers did not step up and drop "NAND_MAYBE_EARLY_INIT" 
totally

this way, existing behavior is retained, board porters have an incentive to 
choose the desired behavior themselves (kill the #warning), and we have 
confidence that we didnt break (most) people.
-mike
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