On 4/11/23 15:07, Mark Brown wrote:
On Mon, Apr 10, 2023 at 11:19:41AM +0300, Matti Vaittinen wrote:
to 6. huhtik. 2023 klo 16.43 Mark Brown (broonie@xxxxxxxxxx) kirjoitti:
I'm not sure what you're expecting there? A device working with itself
shouldn't disrupt any other users.
I have no concrete idea, just a vague uneasy feeling knowing that
devices tend to interact with each other. I guess it is more about the
amount of uncertainty caused by my lack of knowledge regarding what
could be done by these handlers. So, as I already said - if no one
else is bothered by this then I definitely don't want to block the
series. Still, if the error handling should be kept internal to PMBus
- then we should probably either say that consumer drivers must not
(forcibly) turn off the supply when receiving these notifications - or
not send these notifications from PMBus and allow PMBus to decide
error handling internally. (Again, I don't know if any in-tree
consumer drivers do turn off the supply regulator in error handlers -
but I don't think it is actually forbidden). Or am I just making a
problem that does not exist?
I think you are making a problem that doesn't exist.
In this case, sorry folks. I thought consumers could be more 'intrusive'
with the handling of these notifications - which apparently is not true
then. Guenter, I hope the statement from Mark cleared confusion I
caused. I have no further questions about this series.
Like I say I'm not sure how much practical difference it makes to think
too hard about differentiating the errors.
I would do at least two classes.
1) critical class - it is Ok for the consumer to forcibly shut down
the regulator, or maybe the whole system.
2) warning class - it is not Ok to forcibly shut down the regulator.
How severe an issue bad power is will be partly determined by what the
consumer is doing with the power, it's going to be in a fairly narrow
range but there is a range.
No longer related to this patch series - I am still trying to gather
information where the "detection" level PMIC warning IRQs are used in
real-world systems. This might give me some insight how these
notifications are (or could be) used.
Yours,
-- Matti
--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
