Re: [ECOS] RedBoot serial rx interrupts

[Gary Thomas <gthomas@cambridge.redhat.com>]

On 13-Jan-2001 Grant Edwards wrote:
> On Sat, Jan 13, 2001 at 03:11:34PM -0700, Gary Thomas wrote:
> 
>> This looks OK and I think I mispoke before.  GDB_BREAK can and will
>> be set, even for RAM based RedBoot.
> 
> Does that mean that it's normal for RedBoot to unmask serial
> interrupts?
> 
>> However, interrupts should never actually get turned on in the
>> RedBoot environment.  The only place where interrupts are
>> enabled is in the path where the kernel scheduler is enabled.
>> 
>> Are you seeing otherwise?  If so, where?
> 
> My Ethernet driver initialization routine ends up calling
> cyg_drv_isr_lock() and cyg_drv_isr_unlock().  The latter
> enables interrupts.

Maybe we should improve this interface to return an indication of
whether the interrupts _were_ on when "isr_lock()" was called to
avoid this in the future.  I'll think about it.

> 
> I can add #defines to my driver code to turn those into noops
> unless CYGPKG_NET is defined.
> 
> This raises the question: is it OK to call those two routines
> during network device initialization?

It's not necessary.  Interrupts are always off during any system
initialization, so you could just leave this out [and feel safe].