From: Thierry Reding Subject: Re: [PATCH 2/2 v2] pwm_bl: Add mandatory backlight enable regulator Date: Wed, 13 Mar 2013 11:13:28 +0100 Message-ID: <20130313101328.GA28682@avionic-0098.mockup.avionic-design.de> References: <1363126934-8754-1-git-send-email-achew@nvidia.com> <1363126934-8754-3-git-send-email-achew@nvidia.com> <51403F59.2090303@ti.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bg08WKrSYDhXBjb5" Return-path: Received: from moutng.kundenserver.de ([212.227.126.187]:60287 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755506Ab3CMKNl (ORCPT ); Wed, 13 Mar 2013 06:13:41 -0400 Content-Disposition: inline In-Reply-To: <51403F59.2090303@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Peter Ujfalusi Cc: Andrew Chew , acourbot@nvidia.com, linux-omap@vger.kernel.org --bg08WKrSYDhXBjb5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Mar 13, 2013 at 09:56:57AM +0100, Peter Ujfalusi wrote: > On 03/12/2013 11:22 PM, Andrew Chew wrote: [...] > > +static void pwm_backlight_disable(struct backlight_device *bl) > > +{ > > + struct pwm_bl_data *pb =3D dev_get_drvdata(&bl->dev); > > + > > + /* Bail if we are already disabled. */ > > + if (!pb->enabled) > > + return; > > + > > + if (regulator_disable(pb->enable_supply) !=3D 0) > > + dev_warn(&bl->dev, "Failed to disable regulator"); > > + > > + pwm_disable(pb->pwm); > > + > > + pb->enabled =3D false; > > +} >=20 > Would it not be better to have some locking here since the code started t= o use > flag for state tracking? I don't think that's necessary. The backlight core already uses the ops_lock mutex to serial accesses. I just noticed that the documentation mentions that update_lock is used for this purpose, but the code doesn't use it after it is initialized. Still, the ops_lock should be enough. Thierry --bg08WKrSYDhXBjb5 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQIcBAEBAgAGBQJRQFFIAAoJEN0jrNd/PrOhRGEP/1xY96WTzcOgmIu0OyUnNOoe m4/Ah8inwCmuo21GUbCkt+STGEklnF7GUPmPkedt01V4HfdWMQQUj4IjZiWqult8 UaTWkphQjIY/E+ZPk8clXemv1q/FNkz11sMdJFKqGXpBj+EWqEOfMXU0lj0/pZo/ Q//Gvr+SkcmTV2hCLuysVK13cDvCNaEqXiOPOGrzhyTnW+bdduePe+U2UaXaFNF1 JU7SdGSGoFwEiJOdtYq+oYlrfIxBwJv1sLNQZRhhav06RiGh3/4mGPVnmKrGc0CY APFUb0Hn5DEcFaKiB4wmoXvtdTp+dqOIDAGdsrPQ/p4+7IHR84SLCgBZnKJFm+se nHuJESxsGaXVNf4oNdMXV3luQcw/XwD2uSOsrJ11UkDG7GBlCCazxYQYhz0VPhS8 qwOjWTBh/oSklm7IoaWzULvX58e18xXrCjkhbM4etrENtgF0Si7mg6zdmSmntEJ1 9vhEpUGO6rfEs2rC4/RdZKidkQy1L5vN5lmZsZTTpe0V9CmKtq6yVAp/WGu1CZ1A Wo0c2LTfGAx/foSs6pCRWROng8lnVfwUHZD6apgA0VhoIkXGEIXY6a8o4XPlr3Zl vgZb3RMGF2eUNCyBiXbgn5GKCB84lzWa9xKLKyDVl3mbh7Xf0yr4vSKqv/JPmCs/ ev7IpwWIL6k5W74PVspi =WPc3 -----END PGP SIGNATURE----- --bg08WKrSYDhXBjb5--