Re: [RFC PATCH 0/6] Support ROHM BD96801 scalable PMIC

[Matti Vaittinen]

Hi Mark,

On 4/4/24 15:09, Mark Brown wrote:
> On Thu, Apr 04, 2024 at 10:26:34AM +0300, Matti Vaittinen wrote:
>
> > 1. Should we be able to have more than 1 IRQ domain / device?
> > 2. Should regmap_irq support having more than 1 HWIRQ
>
> I would expect each parent interrupt to show up as a separate remap_irq.
>
> > then it seems that reading the IRQ information from the /proc/interrupts
> > works as expected. Here I am making a wild guess that the name of the domain
> > is used as a key for some data-lookups, and having two domains with a same
> > name will either overwrite something or cause wrong domain data to be
> > fetched. (This is just guessing for now).
>
> So if we arrange to supply a name when we register multiple domains
> things should work fine?

Thanks for taking the time to look at my questions :)
I have been debugging this thing whole day today, without getting too 
far :) It seems there is something beyond the name collision though.

After I tried adding '-1' to the end of the other domain name to avoid 
the debugfs name collision I managed to do couple of successful runs - 
after which I reported here that problem seems to be just the naming. 
Soon after sending that mail I hit the oops again even though the naming 
was fixed.

Further debugging shows that the desc->action->name for the last 28 
'errb' IRQs get corrupted. This might point more to the IRQ requester 
side - so I need to further study the BD96801 driver side as well as the 
regulator_irq_helper. I'm having the creeping feeling that at the end of 
the day I need to find the guilty one from the mirror :)

But yes, creating 2 regmap-IRQ controllers for one device seems to 
generate naming conflict in the debugfs - so unless I'm mistaken, with 
the current regmap-IRQ we can't have more than 1 regmap-IRQ entity for a 
single device.

Just please give me some more time to see if I find the cause of the 
corruption and I hope I can write more concrete description. For now it 
was enough for me to hear having more than 1 IRQ domain / device is not 
something on the "DON'T DO THIS" -list.

Yours,
	-- Matti

--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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