From: Rob Herring <robh@kernel.org>
To: "Lothar Waßmann" <LW@KARO-electronics.de>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>,
Jingoo Han <jingoohan1@gmail.com>,
Lee Jones <lee.jones@linaro.org>,
Thierry Reding <thierry.reding@gmail.com>,
Tomi Valkeinen <tomi.valkeinen@ti.com>,
linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pwm@vger.kernel.org,
Marcel Ziswiler <marcel.ziswiler@toradex.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>,
Mark Rutland <mark.rutland@arm.com>,
Pawel Moll <pawel.moll@arm.com>,
devicetree@vger.kernel.org
Subject: Re: [PATCHv2] backlight: pwm_bl: disable PWM when 'duty_cycle' is zero
Date: Wed, 8 Jun 2016 15:06:43 -0500 [thread overview]
Message-ID: <20160608200643.GA13510@rob-hp-laptop> (raw)
In-Reply-To: <1465294429-8570-1-git-send-email-LW@KARO-electronics.de>
On Tue, Jun 07, 2016 at 12:13:49PM +0200, Lothar Waßmann wrote:
> 'brightness' is usually an index into a table of duty_cycle values,
> where the value at index 0 may well be non-zero
> (tegra30-apalis-eval.dts and tegra30-colibri-eval-v3.dts are real-life
> examples).
> Thus brightness == 0 does not necessarily mean that the PWM output
> will be inactive.
> Check for 'duty_cycle == 0' rather than 'brightness == 0' to decide
> whether to disable the PWM.
>
> Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
> ---
> Changes wrt. v1:
> - update binding docs to reflect the change
>
> .../devicetree/bindings/leds/backlight/pwm-backlight.txt | 9 ++++++---
> drivers/video/backlight/pwm_bl.c | 4 ++--
> 2 files changed, 8 insertions(+), 5 deletions(-)
Acked-by: Rob Herring <robh@kernel.org>
next prev parent reply other threads:[~2016-06-08 20:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-07 10:13 [PATCHv2] backlight: pwm_bl: disable PWM when 'duty_cycle' is zero Lothar Waßmann
2016-06-08 20:06 ` Rob Herring [this message]
2016-06-09 13:51 ` Lee Jones
2016-06-10 5:23 ` Lothar Waßmann
2016-06-10 7:44 ` Lee Jones
2016-06-10 10:34 ` Lothar Waßmann
2016-06-10 14:54 ` Lee Jones
2016-06-11 7:08 ` Lothar Waßmann
2016-06-17 14:17 ` Lee Jones
2016-06-20 6:21 ` Lothar Waßmann
2016-06-20 6:29 ` Phil Reid
2016-06-20 8:18 ` Lee Jones
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