Re: [lwip-users] Help with LwIP Modem

[Jeff Barlow]

On 07/09/2016 12:10 PM, address@hidden wrote:
> Jeff Barlow wrote:
> > I think you will find that ChibiOS does much the same. The reasoning
> > as I understand it is to keep ISR code paths as short as possible to
> > minimize latency in hard real time systems.
>
> Without knowing ChibiOS in detail, I'd be interested in knowing what
> would be the actual penalty of removing the need for the API user to
> supply the "bool inIsr"...

I don't claim to be an expert on ChibiOS in particular. It seems fairly 
obvious to me though that inserting extra code in the ISR path that 
inspect some globals only to figure out that it is indeed in an ISR will 
have an adverse effect on latency. ChibiOS is very tightly tuned to 
minimize latency. For some of us this makes the difference between a 
working system and one that almost works.

--
Later,
Jeff