linux-kernel - Re: [RFC/PATCH 11/11] arm: boot: dts: omap: add missing default status for 32k counter

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Message-ID: <20150930141209.GB31865@saruman.tx.rr.com>
Date:	Wed, 30 Sep 2015 09:12:09 -0500
From:	Felipe Balbi <balbi@...com>
To:	Arnd Bergmann <arnd@...db.de>
CC:	<linux-arm-kernel@...ts.infradead.org>,
	Felipe Balbi <balbi@...com>, Tony Lindgren <tony@...mide.com>,
	<daniel.lezcano@...aro.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	<tglx@...utronix.de>,
	Linux OMAP Mailing List <linux-omap@...r.kernel.org>
Subject: Re: [RFC/PATCH 11/11] arm: boot: dts: omap: add missing default
 status for 32k counter

On Wed, Sep 30, 2015 at 10:15:25AM +0200, Arnd Bergmann wrote:
> On Tuesday 29 September 2015 15:44:06 Felipe Balbi wrote:
> > All devices should have a default status. Ignoring
> > the arguments if it should be 'okay' or 'disabled'
> > by default, let's set them all the 'disabled' and
> > have boards enable 32k counter.
> > 
> > Signed-off-by: Felipe Balbi <balbi@...com>
> > 
> 
> The patch looks good, but the description is slightly incorrect:
> There is no reason to list "status='okay'" other than overriding
> the 'disabled' status.
> 
> I'd phrase it something like:
> 
> "We want the use of the 32k counter to be a per-board setting,
> so let's disable it by default in each dtsi file and override the
> setting in the boards. Any board that does not wire up the counter
> should leave it disabled".
> 
> However, if you really want all boards to provide the counter all
> the time, I'd argue that we're better off dropping this patch. We
> use the status="disabled" trick for anything that may or may not
> be working based on the board design, but things that are present
> everywhere don't need this.

okay, so here's the thing. While fiddling with the 32k counter, I noticed
that even though there was no status listed, the thing still initializes
fine. However, when moving 32k to drivers/clocksource and using
CLOCKSOURCE_OF_DECLARE(), 32k would *NOT* probe unless I had an explicit
status = "okay" in DT.

This is where this patch came from. I've used disabled by default
because we just might have a board somewhere which doesn't want to use 32k
counter and having it enabled per-board would help with that. Although,
we could just set status = "disabled" for that one board.

Whatever Tony prefers, I can change the patch accordingly.

-- 
balbi

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