From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-6.0 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id F09DD7D2F0 for ; Wed, 21 Aug 2019 03:24:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727320AbfHUDYJ (ORCPT ); Tue, 20 Aug 2019 23:24:09 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:39290 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727265AbfHUDYJ (ORCPT ); Tue, 20 Aug 2019 23:24:09 -0400 Received: by mail-pg1-f194.google.com with SMTP id u17so473493pgi.6 for ; Tue, 20 Aug 2019 20:24:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=jR0kd8E/wjsd/vD58hqG03ghBqWwRF++q3yiXcP3i4Q=; b=lBPlrnLLKFha+jTbqIiUolRL90RJ36/ooBlOCwIjk2PgLBVZZSZsWTFYSrBFuImrJH FoZUJzRVwjsTmRjRZBBOUvT1a/XAcpNUeVlJbhN/Uoso5NicuB+GGEt5Rc+mt8yAPiqh tnL4cJCxIShM8CQoWPy6A2cDG9dXQyDpe9BQqP5ugjcjZqo/mZ2jRZvQ4UCisw7COV4D BQRhXSt5CUYiNoMPInWyMNoSuwiJzIhgItV8L0lx46LCMC4wpHQLvigC56Zoi3+m6Zwv R+MecQqJV/O+e75TZZRu0o8lx7mqS9AAw1DuW4ctOpPVHym5O+kAQOtKzeILDJgASU2M AM9g== X-Gm-Message-State: APjAAAWGqLg0GzuUqMIHxmbA4ELmYS8V2Li39xoBtoguqrRWrn58YuF9 WmAaEvCupFudWEHPVx9hrznb7Q== X-Google-Smtp-Source: APXvYqx02TH2hHNKYt4nqEYXzwAFlFF9WoYyNeM00zGsD5tPI0GF1ZVQQYIRXONJRCZAIgaLN9mj5A== X-Received: by 2002:a62:e910:: with SMTP id j16mr34286562pfh.123.1566357848815; Tue, 20 Aug 2019 20:24:08 -0700 (PDT) Received: from localhost ([2601:647:5b80:29f7:1bdd:d748:9a4e:8083]) by smtp.gmail.com with ESMTPSA id c13sm22739750pfi.17.2019.08.20.20.24.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Aug 2019 20:24:07 -0700 (PDT) Date: Tue, 20 Aug 2019 20:24:06 -0700 From: Moritz Fischer To: Wu Hao Cc: gregkh@linuxfoundation.org, mdf@kernel.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, atull@kernel.org Subject: Re: [PATCH v5 1/9] fpga: dfl: make init callback optional Message-ID: <20190821032406.GA28625@archbox> References: <1565578204-13969-1-git-send-email-hao.wu@intel.com> <1565578204-13969-2-git-send-email-hao.wu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1565578204-13969-2-git-send-email-hao.wu@intel.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hi, On Mon, Aug 12, 2019 at 10:49:56AM +0800, Wu Hao wrote: > This patch makes init callback of sub features optional. With > this change, people don't need to prepare any empty init callback. > > Signed-off-by: Wu Hao Acked-by: Moritz Fischer > --- > drivers/fpga/dfl.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > index c0512af..96a2b82 100644 > --- a/drivers/fpga/dfl.c > +++ b/drivers/fpga/dfl.c > @@ -271,11 +271,13 @@ static int dfl_feature_instance_init(struct platform_device *pdev, > struct dfl_feature *feature, > struct dfl_feature_driver *drv) > { > - int ret; > + int ret = 0; > > - ret = drv->ops->init(pdev, feature); > - if (ret) > - return ret; > + if (drv->ops->init) { > + ret = drv->ops->init(pdev, feature); > + if (ret) > + return ret; > + } > > feature->ops = drv->ops; You could swap it around maybe like so: int dfl_feature_instance_init() ... { feature->ops = drv->ops; if (drv->ops->init) return drv->ops->init(pdev, feature); return 0; } With the caveat that feature->ops gets always set ... Your call. Thanks, Moritz