Re: [PATCH 0/4] Fix backlight on Armadillo 800 EVA

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

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Hi Thierry,

On Wednesday 11 December 2013 16:15:46 Thierry Reding wrote:
> On Wed, Dec 11, 2013 at 03:48:14AM +0100, Laurent Pinchart wrote:
> > Hello,
> > 
> > Commit 22ceeee16eb8f0d04de3ef43a5174fb30ec18af9 ("pwm-backlight: Add power
> > supply support") added a mandatory power supply for the PWM backlight,
> > resulting in broken backlight on the Armadillo board. This patch set fixes
> > the issue by adding power supplies to board code and DT, and adds proper
> > handling of the panel enable signal through the PWM backlight enable
> > GPIO.
> > 
> > Patch 1/4 fixes a v3.13 regression.
> 
> Actually there should be no regression at all here. The regulator core
> handles this case by providing a dummy if the property hasn't been
> specified in DT.

The regression fixed by 1/4 only affects the legacy (non-DT) Armadillo 800 EVA 
platform. In that case the regulator core doesn't provide a dummy regulator.

> > Strictly speaking patch 3/4 is as well, but the backlight was broken
> > anyway with DT due to the enable GPIO not being handled at all, so
> > there's no need to push it to v3.13.
> 
> If the backlight was broken anyway with DT, how could this new patch break
> it I wonder.

It obviously doesn't change the end result :-) I thought it introduced a new 
bug, but given that the regulator core provides a dummy regulator in this 
case, patch 3/4 is indeed not a regression fix.

-- 
Regards,

Laurent Pinchart

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