From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752426AbcBKStd (ORCPT <rfc822;w@1wt.eu>);
	Thu, 11 Feb 2016 13:49:33 -0500
Received: from mail-wm0-f46.google.com ([74.125.82.46]:38827 "EHLO
	mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751717AbcBKSt2 (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Thu, 11 Feb 2016 13:49:28 -0500
MIME-Version: 1.0
In-Reply-To: <56BCA031.3010702@collabora.com>
References: <1454679181-8949-1-git-send-email-tomeu.vizoso@collabora.com>
 <1454679181-8949-3-git-send-email-tomeu.vizoso@collabora.com>
 <CAMHSBOXRvC7U_KWeg+rX3Qymaos0-3FN6AuaXT2cyP=gAN47mA@mail.gmail.com> <56BCA031.3010702@collabora.com>
From: Gwendal Grignou <gwendal@chromium.org>
Date: Thu, 11 Feb 2016 10:49:07 -0800
X-Google-Sender-Auth: kn1_ceiUYOHPemwnOsYxHLjybfE
Message-ID: <CAMHSBOX8pTyJ+TcSwpfwVtpQcJ0HmHeccONJq0ZmL-Lh4+8z2g@mail.gmail.com>
Subject: Re: [PATCH v1 2/6] mfd: cros_ec: Add MKBP event support
To: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Gwendal Grignou <gwendal@chromium.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        Sameer Nanda <snanda@chromium.org>, Benson Leung <bleung@chromium.org>,
        =?UTF-8?Q?Enric_Balletb=C3=B2?= <enric.balletbo@collabora.co.uk>,
        Vic Yang <victoryang@chromium.org>,
        Vincent Palatin <vpalatin@chromium.org>,
        Randall Spangler <rspangler@chromium.org>,
        Vic Yang <victoryang@google.com>, Olof Johansson <olof@lixom.net>,
        linux-input@vger.kernel.org,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Lee Jones <lee.jones@linaro.org>
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Thu, Feb 11, 2016 at 6:52 AM, Tomeu Vizoso
<tomeu.vizoso@collabora.com> wrote:
>
> On 02/05/2016 06:24 PM, Gwendal Grignou wrote:
> > We should not used kmalloc when get events, these functions are called
> > quite often.
> > Gwendal.
> >
> > On Fri, Feb 5, 2016 at 5:32 AM, Tomeu Vizoso <tomeu.vizoso@collabora.com
> > <mailto:tomeu.vizoso@collabora.com>> wrote:
> >
> >     +static int cros_ec_get_host_command_version_mask(struct
> >     cros_ec_device *ec_dev,
> >     +       u16 cmd, u32 *mask)
> >     +{
> >     +       struct ec_params_get_cmd_versions *pver;
> >     +       struct ec_response_get_cmd_versions *rver;
> >     +       struct cros_ec_command *msg;
> >     +       int ret;
> >     +
> >     +       msg = kmalloc(sizeof(*msg) + max(sizeof(rver), sizeof(pver)),
> >     +                     GFP_KERNEL);
> >     +       if (!msg)
> >     +               return -ENOMEM;
> >
> >  Victor's version in https://chromium-review.googlesource.com/272954
> > looks cleaner: no malloc, no need to cast rver.
>
> I agree that it looks cleaner, but how would you allocate the payload at
> build time if it has to be max(sizeof(*pver), sizeof(*rver))?
For this one, given cros_ec_get_host_command_version_mask() is called
once, a kmalloc is fine.

Gwendal.