Re: [PATCH v4 2/4] i3c: Add more parameters for controllers to the header

[Wolfram Sang <wsa+renesas@sang-engineering.com>]

On Wed, Jul 23, 2025 at 07:50:50PM +0200, Wolfram Sang wrote:
> 
> > > +/* TODO: Document a reason for this value */
> > 
> > Todo? Can you finish it?
> 
> Yes, but in a seperate patch series where the value is to be changed.
> 
> This needs additional testing because I want to update the other I3C
> controller drivers as well.

So, I started the research [1] with the conclusion:

---
The above completion is for the *whole transfer*, though, including the
target response time. Like I2C, it is not specified for I3C. At least, I
couldn't find it and I recall no one at the I3C plugfest could point me
to one as well.

So, this completion timeout is more than just 5.1.2.5. It might make
sense to investigate a more reasonable value. But I don't think this
should be imposed on someone submitting a new driver. It is a dedicated
task. And I am not even sure the result will be a subsystem-wide static
value. It might be a calculated value. Maybe even a driver-specific
calculated value.

So, I think the best we can do until we have this investigation is to
keep drivers consistent with the historically grown value.
---

Based on this, I will send V5 and move XFER_TIMEOUT back into the
driver. We don't know yet if a subsystem-wide static default value is
actually the right way.

[1] https://lore.kernel.org/r/aIH1zUb8tyIlyC3S@shikoro


-- 
linux-i3c mailing list
linux-i3c@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-i3c