Date: Thu, 31 Aug 2017 10:18:20 +0200
From: Pavel Machek <pavel@ucw.cz>
To: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Chris Healy <cphealy@gmail.com>, Lucas Stach <l.stach@pengutronix.de>,
        Lee Jones <lee.jones@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jeff White <Jeff.White@zii.aero>
Subject: Re: [PATCH v6 1/2] platform: Add driver for RAVE Supervisory
 Processor
Message-ID: <20170831081820.GB9597@amd>
References: <20170828163131.24815-1-andrew.smirnov@gmail.com>
 <20170828163131.24815-2-andrew.smirnov@gmail.com>
 <20170830105515.GA4926@amd>
 <CAHQ1cqFsEPJ1qDbOm8qt0DDv-voua_psRxVdN959=go_AATDmA@mail.gmail.com>
 <20170830203817.GA15462@amd>
 <35163bfd-d34f-40af-2494-340b6fe92b03@cogentembedded.com>
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On Thu 2017-08-31 11:10:35, Nikita Yushchenko wrote:
>=20
>=20
> 30.08.2017 23:38, Pavel Machek wrote:
> > Hi!
> >=20
> >>>> +                 * 9  -> Illegal Trap
> >>>> +                 * 10 -> Unknown
> >>>> +                 * 11 -> Crew Panel Requested
> >>>
> >>> Anyway... If you move management chip to .. I don't know, i2c, the
> >>> path would change. Also it would be different path on N900. Userland
> >>> should not have to deal with this.
> >>>
> >>> And... this should really be string, as the list will need to grow on
> >>> different hardware.
> >>
> >> I think we have a misunderstanding, with this part of the patch set I
> >> am not trying to propose a generic ABI that would be useful for any
> >> other driver but this one. Hence the lack of concern for different
> >=20
> > Yes, but sorry, that's no-go.  Kernel should hide differences between
> > different machiens, and it should be rather easy in this case.
>=20
> There is an interest to have reset reason exported on other ZII hardware
> as well.
>=20
> I think that trying to make this generic is purely synthetic. This
> information is board-specific per it's nature, it comes from what board
> is designed for, different boards have quite different sets of possible
> reset reasons. What is needed is - pass this board-specific information
> to board-specific user space.
>=20
> What's proper API for that, if not a sysfs attribute?

Please go through the thread.

Sysfs attribute is okay, but:

1) it should probably be a string

2) it should certainly be superset of all the reasons

3) it should be in generic place, say /sys/power/reset_reason

4) it should be documented what each state means
									Pavel
--=20
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo=
g.html

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