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

Detlef Vollmann dv at vollmann.ch
Thu Mar 12 22:07:36 CET 2009


Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 02:58 Wed 25 Feb     , Detlef Vollmann wrote:

>>  /*
>> + * This code essentially ignores the settings of AT91_MASTER_CLOCK
>> + * and CONFIG_SYS_HZ, so we just bail out if they're not set to
>> + * the canonical values.
>> + */
>> +#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.
If these projects change to a current U-Boot version, they
fail.  And I prefer a loud compile time fail over a silent
runtime fail.
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.

>> +/* 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.

Best Regards,
   Detlef


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