Re: [PATCH V2 03/19] irqchip: crossbar: Skip some irqs from getting mapped to crossbar

On Friday 13 June 2014 09:10 AM, Jason Cooper wrote:

On Fri, Jun 13, 2014 at 12:26:10PM +0530, Sricharan R wrote:

quoted

On Thursday 12 June 2014 07:35 PM, Jason Cooper wrote:

...

quoted

quoted

Do you have other changes outside of irqchip depending on this series?
If so, I can set up a topic branch for you guys to base off of.
Otherwise, I'll just apply them to irqchip/core when they're ready.

 There are dts changes which are dependent upon this series.

  http://www.spinics.net/lists/linux-omap/msg108116.html

In general, dts changes shouldn't depend on code changes or vice-versa.
If they do, that's an indicator that we're breaking compatibility with
older dtbs.

Thats true. The case with cross-bar though is the feature wasn't
completly supported so far before this series. Perhaps the the initial
bindings should have been marked unstable. 
 

Looking at the dra7.dtsi changes, we're redefining the interrupt
property, which can't be good. :(

Perhaps a better solution would be to add a property, say 'ti,cross-irq'
that is the exact same format as 'interrupts', but is used by the
crossbar driver?

We have gone over those earlier and it was agreed to re-use interrupt
properties and for special cases, define a cross-bar property to describe
it.
 

I'm not convinced of this yet, I suspect we may not actually have a
dependency between the dtsi changes and the code changes.  We would have
the ugly "if you have the crossbar node, 'interrupts' means X, if not it
means Y" in the binding docs.  But the absence of the node prevents the
crossbar driver from re-interpreting the interrupts property.

In ideal cross-bar hardware you don't need the assumption "if you have the
crossbar node, 'interrupts' means X, if not it means Y"

It is purely because the cross-bar irq router hardware has few nasty
bugs which needs those special handling. And thats the reason, the
property was added.

Have you tried booting all the different scenarios?  eg:

  old dtb, new driver
  new dtb, old driver
  old dtb, old driver
  new dtb, new driver

Old driver wasn't complete as mentioned and hence the above
combinations becomes bit irrelevant.

Regards,
Santosh


--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html