From mboxrd@z Thu Jan  1 00:00:00 1970
From: Philipp Zabel <p.zabel@pengutronix.de>
Subject: Re: [PATCH v2] pwm-backlight: fix the panel power sequence
Date: Tue, 03 Nov 2015 12:08:44 +0100
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To: YH Huang <yh.huang@mediatek.com>
Cc: linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, Jingoo Han <jingoohan1@gmail.com>, Tomi Valkeinen <tomi.valkeinen@ti.com>, Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>, linux-kernel@vger.kernel.org, Thierry Reding <thierry.reding@gmail.com>, linux-mediatek@lists.infradead.org, Sascha Hauer <kernel@pengutronix.de>, Matthias Brugger <matthias.bgg@gmail.com>, yingjoe.chen@mediatek.com, Lee Jones <lee.jones@linaro.org>, linux-arm-kernel@lists.infradead.org

Hi YH,

Am Dienstag, den 03.11.2015, 16:11 +0800 schrieb YH Huang:
> > The reasoning is that devices where there is no phandle link pointing to
> > the backlight (for example from a simple-panel node), we should keep the
> > current default behaviour (enable during probe).
> 
> I have a little problem for the current default behaviour.
> Should we enable during probe?

Here I mean enabling the backlight (at the end of the probe function),
not enabling the GPIO already when requesting it.

> Before this patch ( http://patchwork.ozlabs.org/patch/324690/ ),
> we disable "enable-gpio" in the probe function.

While before this patch the GPIO would be initialized in the disabled
state, the call to backlight_update_status at the end of the probe
function would still enable the backlight afterwards.

regards
Philipp