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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 1C79DC4742C for ; Tue, 3 Nov 2020 08:16:50 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D1E1E206E3 for ; Tue, 3 Nov 2020 08:16:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D1E1E206E3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ACULAB.COM Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=amd-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 68B486EC03; Tue, 3 Nov 2020 08:15:04 +0000 (UTC) X-Greylist: delayed 305 seconds by postgrey-1.36 at gabe; Mon, 02 Nov 2020 22:37:08 UTC Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [207.82.80.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id 889766E40C for ; Mon, 2 Nov 2020 22:37:08 +0000 (UTC) Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mtapsc-3-j6bXPPu-Nl6LRhxQXu1CQQ-1; Mon, 02 Nov 2020 22:30:46 +0000 X-MC-Unique: j6bXPPu-Nl6LRhxQXu1CQQ-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Mon, 2 Nov 2020 22:30:45 +0000 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Mon, 2 Nov 2020 22:30:45 +0000 From: David Laight To: 'Greg KH' , Alex Deucher Subject: RE: [PATCH] drm/amdgpu: do not initialise global variables to 0 or NULL Thread-Topic: [PATCH] drm/amdgpu: do not initialise global variables to 0 or NULL Thread-Index: AQHWsVQzuHsYTLqYC0GrzZhKR8oU56m1aalA Date: Mon, 2 Nov 2020 22:30:45 +0000 Message-ID: References: <20201102184147.GA42288@localhost> <20201102201040.GA2433494@kroah.com> In-Reply-To: <20201102201040.GA2433494@kroah.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US X-Mailman-Approved-At: Tue, 03 Nov 2020 08:15:01 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Deepak R Varma , David Airlie , Daniel Vetter , LKML , amd-gfx list , Melissa Wen , Maling list - DRI developers , Daniel Vetter , Alex Deucher , =?iso-8859-1?Q?Christian_K=F6nig?= Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" From: Greg KH > Sent: 02 November 2020 20:11 > > On Mon, Nov 02, 2020 at 02:43:45PM -0500, Alex Deucher wrote: > > On Mon, Nov 2, 2020 at 1:42 PM Deepak R Varma wrote: > > > > > > Initializing global variable to 0 or NULL is not necessary and should > > > be avoided. Issue reported by checkpatch script as: > > > ERROR: do not initialise globals to 0 (or NULL). > > > > I agree that this is technically correct, but a lot of people don't > > seem to know that so we get a lot of comments about this code for the > > variables that are not explicitly set. Seems less confusing to > > initialize them even if it not necessary. I don't have a particularly > > strong opinion on it however. > > The kernel coding style is to do it this way. You even save space and > time by doing it as well :) Uninitialised globals end up as 'named common' (variables that are their own code section - from FORTRAN) until the final link puts them into the .bss. Globals initialised to 0 go into the .bss of the object file being created. So both end up in the final .bss. If the code goes into a module you aren't allowed 'common' data in a module to every global must be initialised. I'm surprised checkpatch complains. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales) _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx