From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E516C0044C for ; Wed, 7 Nov 2018 17:23:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 741EA2081D for ; Wed, 7 Nov 2018 17:23:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 741EA2081D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731413AbeKHCzC (ORCPT ); Wed, 7 Nov 2018 21:55:02 -0500 Received: from mail.bootlin.com ([62.4.15.54]:38053 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727576AbeKHCzB (ORCPT ); Wed, 7 Nov 2018 21:55:01 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id 06AAE208CB; Wed, 7 Nov 2018 18:23:40 +0100 (CET) Received: from localhost (242.171.71.37.rev.sfr.net [37.71.171.242]) by mail.bootlin.com (Postfix) with ESMTPSA id CC4D3208CB; Wed, 7 Nov 2018 18:23:39 +0100 (CET) Date: Wed, 7 Nov 2018 18:23:40 +0100 From: Alexandre Belloni To: Claudiu.Beznea@microchip.com Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, sre@kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 2/4] power: reset: at91-poweroff: move shdwc related data to one structure Message-ID: <20181107172340.GF21694@piout.net> References: <1541416443-4321-1-git-send-email-claudiu.beznea@microchip.com> <1541416443-4321-3-git-send-email-claudiu.beznea@microchip.com> <20181106210933.GU24212@piout.net> <6719a808-e704-3c63-f592-3b90d44ccbfe@microchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6719a808-e704-3c63-f592-3b90d44ccbfe@microchip.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/11/2018 14:54:17+0000, Claudiu.Beznea@microchip.com wrote: > Hi Alexandre, > > On 06.11.2018 23:09, Alexandre Belloni wrote: > > Hi Claudiu, > > > > On 05/11/2018 11:14:26+0000, Claudiu.Beznea@microchip.com wrote: > >> static int __init at91_poweroff_probe(struct platform_device *pdev) > >> @@ -154,16 +160,22 @@ static int __init at91_poweroff_probe(struct platform_device *pdev) > >> u32 ddr_type; > >> int ret; > >> > >> + at91_shdwc = devm_kzalloc(&pdev->dev, sizeof(*at91_shdwc), GFP_KERNEL); > >> + if (!at91_shdwc) > >> + return -ENOMEM; > >> + > > > > Is there any real benefit that will offset the time lost for that > > allocation at boot time? > > No, I haven't run benchmarks on this. I only wanted to have them grouped in > one structure. Please let me know if you have some tests in mind. > Well, it is probably not much but small things adds up. Havinf it as a global structure is probably good enough. > > > > I understand you are then testing at91_shdwc to know whether the driver > > already probed once. But, the driver will never probe twice as there is > > only one shutdown controller on the SoC and anyway, If it was to probe > > twice, it will still work as expected. > > I had in mind the scenario where the driver would be compiled as module. I > know insmod already does this checking. I'm ok to remove this checking. I > will do it in next version. With this I will also remove devm_kzalloc() of > at91_shdwc. > Thanks, -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com