linux-kernel - Re: Nokia N900 retention mode in v4.6, camera buttons fun

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Date:	Tue, 12 Apr 2016 14:30:13 +0200
From:	Pavel Machek <pavel@....cz>
To:	Tony Lindgren <tony@...mide.com>
Cc:	pali.rohar@...il.com, sre@...nel.org,
	kernel list <linux-kernel@...r.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
	linux-omap@...r.kernel.org, khilman@...nel.org,
	aaro.koskinen@....fi, ivo.g.dimitrov.75@...il.com,
	patrikbachan@...il.com, serge@...lyn.com,
	Tomi Valkeinen <tomi.valkeinen@...com>
Subject: Re: Nokia N900 retention mode in v4.6, camera buttons fun

Hi!

> > > Ok, it works now. I was doing tests in daylight so it was poorly
> > > visible. The right part of keyboard stays lit (but that's expected
> > > AFAICT), but the left part blinks.
> > 
> > During idle, both should go off and are doing so for me. Both LEDs off
> > indicates off mode, left LED off is for retention mode. So you still
> > have something blocking off mode, maybe check:
> > 
> > echo 1 > /sys/kernel/debug/pm_debug/enable_off_mode
> 
> What is the power difference between retention and off? I'm now down
> to cca 25mA, which should be around 50 hours standby time. Not ideal,
> but should be usable.
> 
> In the meantime, I found what is causing the rention mode to break for
> me: CONFIG_HSI (aka wireless modem support). With HSI off, it seems to work.
> 
> I still get problems with the camera button, in config similar to
> defconfig.  For some reason, I'm even getting (autorepeating) ^@ on
> console. As long as I hold camera button down, I even get it into off
> mode for brief period.

Ok, if I turn off CONFIG_KEYBOARD_GPIO, I get it into off
mode... once per screen blank, for about a second. (Does CONFIG_KEYBOARD_GPIO also cause
problems for you?)

Any idea why it enters off mode only once after each screenblank?

Best regards,
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html