From: Pavel Machek <pavel@ucw.cz>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: rpurdie@rpsys.net, j.anaszewski@samsung.com,
linux-leds@vger.kernel.org,
"João Paulo Rechi Vita" <jprvita@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
"Darren Hart" <dvhart@infradead.org>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
platform-driver-x86@vger.kernel.org, linux-api@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux@endlessm.com,
"João Paulo Rechi Vita" <jprvita@endlessm.com>
Subject: Re: custom ioctl-based interface to control LED in networking (was Re: [PATCHv2 09/10] rfkill: Userspace control for airplane mode)
Date: Thu, 25 Feb 2016 10:06:36 +0100 [thread overview]
Message-ID: <20160225090636.GA32652@amd> (raw)
In-Reply-To: <1456320693.2050.30.camel@sipsolutions.net>
On Wed 2016-02-24 14:31:33, Johannes Berg wrote:
> On Wed, 2016-02-24 at 13:14 +0100, Pavel Machek wrote:
> >
> > Why would it need to? It could look at default triggers for the led
> > if it really wanted to.
>
> And then it needs to change them; if anything goes wrong error recovery
> is practically impossible since the trigger information is lost
> forever.
Well, conventional way to solve this is to simply name the led
"acer::airplane"... that way it is persistent. We already do that for
display/keyboard backlights.
> It's not my position to decide which combinations some system
> integrator or userspace developer might find useful.
>
> Even when we add parameters to a trigger (I don't see a generic way to
> do that, but please do enlighten me), you're now ignoring the issue of
> the userspace controlled GSM modem...
Take a look at the blinking triggers.
> > > Really what you have here is a concept of "airplane mode", and that
> > > concept is specific to the rfkill subsystem. This happens to affect
> > > mostly an LED trigger, today, but as a concept it's something that
> > > *should* be managed within the rfkill subsystem.
> >
> > How is that concept used outside the LEDs? What semantics does
> > "airplane mode" have? You tried to explain "airplane mode" is not
> > well defined up in this thread...
>
> I'd say it's well-defined for any given set of system software, so if
> e.g. NetworkManager decides to define it one way, and connman another
> way, there's a definition but the kernel need not interfere with it.
So... the LED changes meaning during boot? That's surely not a nice
solution.
So... you rather store bit in a kernel with unclear semantics,
explaining "oh I need to leave the flexibility to userland"? Sorry,
that's just ugly.
> > I'm not saying that. I'm saying that LED maintainers should be Cced,
> > to keep the interfaces consistent.
>
> I pretty much have to read it that way, since the LED API is in no way
> impacted by these changes. Here's a new trigger, with some magic inner
> working. No impact on the LED API.
New LED trigger and new ioctl for LED control... not matching how LEDs
are normally controlled.
Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2016-02-25 9:06 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-22 16:36 [PATCHv2 00/10] RFKill airplane-mode indicator João Paulo Rechi Vita
2016-02-22 16:36 ` [PATCHv2 01/10] rfkill: Improve documentation language João Paulo Rechi Vita
2016-02-22 16:36 ` [PATCHv2 02/10] rfkill: Remove extra blank line João Paulo Rechi Vita
2016-02-22 16:36 ` [PATCHv2 03/10] rfkill: Point to the correct deprecated doc location João Paulo Rechi Vita
2016-02-22 16:36 ` [PATCHv2 04/10] rfkill: Move "state" sysfs file back to stable João Paulo Rechi Vita
2016-02-23 20:45 ` Pavel Machek
2016-02-22 16:36 ` [PATCHv2 05/10] rfkill: Factor rfkill_global_states[].cur assignments João Paulo Rechi Vita
2016-02-22 16:36 ` [PATCHv2 06/10] rfkill: Add documentation about LED triggers João Paulo Rechi Vita
2016-02-22 16:36 ` [PATCHv2 07/10] rfkill: Create "rfkill-airplane-mode" LED trigger João Paulo Rechi Vita
2016-02-22 16:36 ` [PATCHv2 08/10] rfkill: Use switch to demux userspace operations João Paulo Rechi Vita
2016-02-26 17:59 ` Jouni Malinen
2016-02-29 22:30 ` João Paulo Rechi Vita
2016-02-29 22:39 ` Jouni Malinen
2016-03-01 13:43 ` Johannes Berg
2016-03-01 16:15 ` João Paulo Rechi Vita
2016-03-08 14:01 ` João Paulo Rechi Vita
2016-02-22 16:36 ` [PATCHv2 09/10] rfkill: Userspace control for airplane mode João Paulo Rechi Vita
2016-02-22 19:31 ` [PATCHv3] " João Paulo Rechi Vita
2016-02-23 20:45 ` [PATCHv2 09/10] " Pavel Machek
2016-02-23 20:55 ` Johannes Berg
2016-02-23 21:45 ` Pavel Machek
2016-02-24 9:01 ` Johannes Berg
2016-02-24 10:46 ` custom ioctl-based interface to control LED in networking (was Re: [PATCHv2 09/10] rfkill: Userspace control for airplane mode) Pavel Machek
2016-02-24 11:01 ` Johannes Berg
2016-02-24 12:14 ` Pavel Machek
2016-02-24 13:31 ` Johannes Berg
2016-02-25 9:06 ` Pavel Machek [this message]
2016-02-22 16:36 ` [PATCHv2 10/10] rfkill: Notify userspace of airplane-mode state changes João Paulo Rechi Vita
2016-02-22 17:00 ` [PATCHv2 00/10] RFKill airplane-mode indicator Dan Williams
2016-02-22 19:35 ` João Paulo Rechi Vita
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