From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Neukum Subject: Re: [PATCH v2 01/24] input: Add ff-memless-next module Date: Wed, 23 Apr 2014 19:06:08 +0200 Message-ID: <1398272768.23603.1.camel@linux-fkkt.site> References: <1398175209-9565-1-git-send-email-madcatxster@devoid-pointer.net> <1398175209-9565-2-git-send-email-madcatxster@devoid-pointer.net> <1398255179.32091.1.camel@linux-fkkt.site> <20140423155923.GB10531@core.coreip.homeip.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:38248 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751188AbaDWRGL (ORCPT ); Wed, 23 Apr 2014 13:06:11 -0400 In-Reply-To: <20140423155923.GB10531@core.coreip.homeip.net> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Dmitry Torokhov Cc: Michal =?ISO-8859-1?Q?Mal=FD?= , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, jkosina@suse.cz, elias.vds@gmail.com, anssi.hannula@iki.fi, simon@mungewell.org On Wed, 2014-04-23 at 08:59 -0700, Dmitry Torokhov wrote: > On Wed, Apr 23, 2014 at 02:12:59PM +0200, Oliver Neukum wrote: > > On Tue, 2014-04-22 at 15:59 +0200, Michal Mal=C3=BD wrote: > > > +/* Some devices might have a limit on how many uncombinable effe= cts > > > + * can be played at once */ > > > +static int mlnx_upload_conditional(struct mlnx_device *mlnxdev, > > > + const struct ff_effect *effect= ) > > > +{ > > > + struct mlnx_effect_command ecmd =3D { > > > + .cmd =3D MLNX_UPLOAD_UNCOMB, > > > + .u.uncomb.id =3D effect->id, > > > + .u.uncomb.effect =3D effect > > > + }; > > > + return mlnxdev->control_effect(mlnxdev->dev, mlnxdev->pri= vate, > > > &ecmd); > > > +} > > > + > >=20 > > This mean you are building the structure on the stack > >=20 > > 1. Are you sure nobody retains a reference? > > 2. That is needlessly inefficient >=20 > Why is it inefficient? The compiler has to include the data structure and then make a memcopy to the stack. Instead a pointer to the predined structure could be passed. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-input" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html