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

From: Marc Zyngier
Date: Wed Oct 31 2018 - 14:42:36 EST


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... ;-)

M.
--
Jazz is not dead. It just smells funny...