Re: [PATCH v2 09/10] irqchip: ti-sci-inta: Add support for Interrupt Aggregator driver

From: Santosh Shilimkar
Date: Wed Oct 31 2018 - 14:48:45 EST

On 10/31/2018 11:42 AM, Marc Zyngier wrote:
On 31/10/18 18:38, Santosh Shilimkar wrote:
On 10/31/2018 11:21 AM, Marc Zyngier wrote:
Hi Grygorii,


Well, I'm convinced that we do not want a networking driver to be tied
to an interrupt architecture, and that the two should be completely
independent. But that's my own opinion. I can only see two solutions
moving forward:

1) You make the IA a real interrupt controller that exposes real
interrupts (one per event), and write your networking driver
independently of the underlying interrupt architecture.

2) you make the IA an integral part of your network driver, not exposing
anything outside of it, and limiting the interactions with the IR
*through the standard IRQ API*. You duplicate this knowledge throughout
the other client drivers.

I believe that (2) would be a massive design mistake as it locks the
driver to a single of the HW (and potentially a single revision of the
firmware) while (1) gives you the required level of flexibility by
hiding the whole event "concept" at a single location.

Yes, (1) makes you rewrite your existing, out of tree drivers. Oh well...

My preference is also not tie the network driver with IA. BTW, this is
very standard functionality with other network drivers too. And this
is handled using MSI-X.

So strong NO for 1) from me as well.

Err. Are you opposing to (1) or (2)? From the above, I cannot really
tell... ;-)

I mixed it up, sorry. I meant NO for (2), i.e No for making IA part of
the network driver.