From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH] pwm-backlight: fix bogus request for GPIO#0 when instantiated from DT Date: Wed, 20 Aug 2014 13:17:56 +0100 Message-ID: <20140820121756.GK4266@lee--X1> References: <1408516716-28828-1-git-send-email-LW@KARO-electronics.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-ig0-f174.google.com ([209.85.213.174]:35797 "EHLO mail-ig0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752326AbaHTMSC (ORCPT ); Wed, 20 Aug 2014 08:18:02 -0400 Received: by mail-ig0-f174.google.com with SMTP id c1so11516369igq.1 for ; Wed, 20 Aug 2014 05:18:01 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1408516716-28828-1-git-send-email-LW@KARO-electronics.de> Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: Lothar =?iso-8859-1?Q?Wa=DFmann?= Cc: Bryan Wu , Jean-Christophe Plagniol-Villard , Jingoo Han , Thierry Reding , Tomi Valkeinen , linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org On Wed, 20 Aug 2014, Lothar Wa=C3=9Fmann wrote: > commit 257462dbf3ed ("pwm-backlight: switch to gpiod interface") > introduced a regression leading to acquiring a bogus GPIO-0 when > configured from DT without an 'enable-gpios' property. > The driver will happily accept the 0 initialized 'enable_gpio' member > of the struct platform_pwm_backlight_data as valid gpio number, and > request this GPIO as enable pin. In case of multiple driver instances= , > the second will fail to register with the error message: > pwm-backlight backlight1.23: failed to request GPIO#0: -16 >=20 > Fix this by setting enable_gpio in the pdata struct to -EINVAL. >=20 > Signed-off-by: Lothar Wa=C3=9Fmann > --- > drivers/video/backlight/pwm_bl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Applied to -fixes with Thierry's Ack and the blank line left. > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlig= ht/pwm_bl.c > index d7a3d13..e6ef6b4 100644 > --- a/drivers/video/backlight/pwm_bl.c > +++ b/drivers/video/backlight/pwm_bl.c > @@ -172,7 +172,7 @@ static int pwm_backlight_parse_dt(struct device *= dev, > data->dft_brightness =3D value; > data->max_brightness--; > } > - > + data->enable_gpio =3D -EINVAL; > return 0; > } > =20 --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog