[U-Boot] [PATCH v2] at91: change CONFIG_SYS_HZ to 1000

[Wolfgang Denk]

Dear Detlef Vollmann,

In message <49B97998.2080805 at vollmann.ch> you wrote:
>
> >> +#if (CONFIG_SYS_HZ != 1000)
> >> +#error "CONFIG_SYS_HZ must be set to 1000 for this CPU"
> >> +#endif
> > no need please remove
> As I already wrote in another message, I don't think so.
> All current boards that use U-Boot on that chip family need to
> use a value of 1000000 for CONFIG_SYS_HZ, and most of these
> config files are not in the public U-Boot tree.

We do not add dead code or provide other provisions for code that may
exist in out-of-tree ports.

> If these projects change to a current U-Boot version, they

> And I can't see any reason for not having that check: it doesn't
> clutter the code, has no measurable effects on compile time,
> and absolutely no effects for the runtime.

Yes, it does clutter the code. It is dead code. We could as well add

	#if 1 != 1
	#error Armageddon!
	#endif

or similar to each and every source fine, just in case hell breaks
lose.

> >> +/* We leave some leeway for the master clock... */
> >> +#if (AT91_MASTER_CLOCK < 85000000) || (AT91_MASTER_CLOCK > 115000000)
> >> +#error "AT91_MASTER_CLOCK must be set to 100000000 for this CPU"
> >> +#endif
> > why?
> The old implementation simply assumes that AT91_MASTER_CLOCK has a
> value of 100000000, and I didn't change that.
> But the config file for afeb9260 sets it to a value of 89999598,
> and I can't change that as I don't know that board, but it's
> near enough to 100000000 to accept that.
> And I noticed that only because I had the check there in the
> first place, so it didn't compile with MAKEALL when I only checked
> for the exact value of 100000000.

That's a very obscure reasoning, me thinks. We don't  understand  the
89999598,  so  we  accept  85000000...115000000  ?  That's true vodoo
programming.

Best regards,

Wolfgang Denk

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