[U-Boot] [PATCH 01/21] Define new system_restart() and emergency_restart()

[Wolfgang Denk]

Dear Graeme Russ,

In message <4D88909A.80508 at gmail.com> you wrote:
>
> > That would be a layer higher than do_reset() (for example, in
> > panic()).
> 
> Hmmm, but panic() is defined in lib/vsprintf.c with no possibility for it
> to be overridden in any arch or board specific way

I guess that could be helped.

> > panic() is a higher software layer. It probably results in calling
> > reset() in the end.
> 
> Unless CONFIG_PANIC_HANG is defined...

> reset():
>   - does not exist (as far as I can tell)

reset() is used as symbol in many arm, mips and sparc start.S files

> I still like the idea of passing a 'reason' to reset() / panic() - Could we
> change panic() to:
...
> Anywhere in the code that needed to hang has a choice - hang(reason) or
> panic(reason | PANIC_FLAG_HANG)

I don't think you resonably decide which to use in common code.

Most calls to panic() appear to come from proprietary flash drivers
anyway - most of which should be dropped as they could use the CFI
driver instead. [And if you look at the actual code, the tests for
these panic()s can easily be computed at compile time, so these are
stupid aniway.]

Others 

Now, assume for things like this:

	panic("No working SDRAM available\n");

or like handling undefined instructions or that - what would be more
useful - to hang() to to reset()? ;-)


Can you please show me a specific case where you would use such
different arguments to panic() in the existing code?

> Default implementations of hang() and reset() would just ignore reason.
> Board specific code can use reason to do one last boot_progress(), set LED
> states etc.

That should be done at a higher software layer.

Best regards,

Wolfgang Denk

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