Re: [PATCH V2 05/19] irqchip: crossbar: Change allocation logic by reversing search for free irqs

Hi Jason,

On Thursday 12 June 2014 06:26 PM, Jason Cooper wrote:

On Thu, Jun 12, 2014 at 05:23:13PM +0530, Sricharan R wrote:

quoted

From: Nishanth Menon <nm@ti.com>

Reverse the search algorithm to ensure that address mapping and IRQ
allocation logics are proper. This can open up new bugs which are
easily fixable rather than wait till allocation logic approaches
the limit to find new bugs.

Could you expand on this logic some more?  What class of bugs are you
hoping to discover more easily?

class 1. address space errors -> example:
reg = <a size_b>
ti,max-irqs =  is a wrong parameter

class 2: irq-reserved list - which decides which entries in the
address space is not actually wired in

class 3: wrong list of routable-irqs.

in general allocating from max to min tends to have benefits in
ensuring the different issues that may be present in dts is easily
caught at definition time, rather than at a later point in time.


Regards,
 Sricharan