Realtime interrupt handling in driver

Realtime interrupt handling in driver

[Russell Johnson]

Hello,

In my driver that I have been converting to support OOB functionality with the EVL core, I have an interrupt handler that handles all interrupts from a device sitting on the PCIe bus. I was reading through the information on your wiki about interrupt pipelining in Dovetail. I was confused a bit on if there is work that I need to do in order to get interrupts & interrupt handlers to run out-of-band (and not be preempted by in-band linux processing), or if the EVL core takes care of that for me? If there is work I need to do with interrupt config & interrupt handlers in order to make them able to run out-of-band, where do I need to start?

Thanks!

Russell

RE: Realtime interrupt handling in driver

[Chen, Hongzhan]

>-----Original Message-----
>From: Xenomai <xenomai-bounces@xenomai.org> On Behalf Of Russell Johnson via Xenomai
>Sent: Wednesday, February 23, 2022 8:10 AM
>To: xenomai@xenomai.org
>Subject: Realtime interrupt handling in driver
>
>Hello,
>
>In my driver that I have been converting to support OOB functionality with the EVL core, 
>I have an interrupt handler that handles all interrupts from a device sitting on the PCIe bus.
>I was reading through the information on your wiki about interrupt pipelining in Dovetail. 
>I was confused a bit on if there is work that I need to do in order to get interrupts & interrupt 
>handlers to run out-of-band (and not be preempted by in-band linux processing), or if the EVL core 

It was supposed that you already went through introduction about dovetail irq handling and request irq 
for your driver as described in  [1]. Dovetail would handle oob interrupt after then per my understanding.

Regards

Hongzhan Chen

[1]: https://evlproject.org/dovetail/pipeline/irq_handling/

>takes care of that for me? If there is work I need to do with interrupt config & interrupt handlers 
>in order to make them able to run out-of-band, where do I need to start?
>
>Thanks!
>
>Russell
>

Re: Realtime interrupt handling in driver

[Philippe Gerum]

Russell Johnson via Xenomai <xenomai@xenomai.org> writes:

> Hello,
>
> In my driver that I have been converting to support OOB functionality
> with the EVL core, I have an interrupt handler that handles all
> interrupts from a device sitting on the PCIe bus. I was reading
> through the information on your wiki about interrupt pipelining in
> Dovetail. I was confused a bit on if there is work that I need to do
> in order to get interrupts & interrupt handlers to run out-of-band
> (and not be preempted by in-band linux processing), or if the EVL core
> takes care of that for me?
> If there is work I need to do with
> interrupt config & interrupt handlers in order to make them able to
> run out-of-band, where do I need to start?
>
> Thanks!
>
> Russell

[1] describes the general flow, this is a bit outdated starting from the
upcoming kernel v5.17 series [2], but the logic remains the same though.
[3] explains why and how to fix up the irqchip handlers for IRQ
pipelining.

[1] https://evlproject.org/dovetail/porting/irqflow/
[2] https://source.denx.de/Xenomai/xenomai4/linux-evl/-/tree/v5.17-evl-rebase
[3] https://evlproject.org/dovetail/pipeline/irq_handling/

-- 
Philippe.