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=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 65595C4332D for ; Thu, 19 Mar 2020 10:18:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 34B71206D7 for ; Thu, 19 Mar 2020 10:18:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="EYB0H32K" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727064AbgCSKSg (ORCPT ); Thu, 19 Mar 2020 06:18:36 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:51554 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726825AbgCSKSf (ORCPT ); Thu, 19 Mar 2020 06:18:35 -0400 Received: by mail-wm1-f66.google.com with SMTP id c187so1444390wme.1 for ; Thu, 19 Mar 2020 03:18:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to; bh=9orDqus34XDuXi5i1KvF+t2rP3oN+I1lofE3FxXqw5k=; b=EYB0H32KYUNpFmHyD2o5deHe2/46kUttKOvnFsphFEu9WTmAXYn15ERROmCC1kQU97 B3kN01ywJLlqlOQ5cw4sM1AiJgV4MNgUA5G1WD2OheCrVtTEMUUe0YertrKzWZT4kbsJ /zekAZHkZmYXhNP+hgoo0zBgl2x79eOtQ9IKM= 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 :mail-followup-to:references:mime-version:content-disposition :in-reply-to; bh=9orDqus34XDuXi5i1KvF+t2rP3oN+I1lofE3FxXqw5k=; b=K5vnBaDQuAWvRphNrp2Gu6J0cVlCOf59yjYN+5DGBXQh9+OpOxYkyBniWvWdSqgLED 6V+d5jUZ7kWijNHxX4j+1pwm9xbDd/gPi41yKUWv6JQcntCutADl7hOfBK0qFEjA3Y9I X6M3l68qowOQ/m6CT85O+lp19NhydjLhM5JvyiX5Mo3Z+ZCCfm6tfyP0ZFP0r67Ymftm 6j2EB7h46YQhgSigMWsdyBZ0eL/4Riz3Gyai+Xhr6vqSUZaHtxHBXlwxr2u+dAxqO1Hd zWqGbMLxtxZXrSAtuWhEOUhOsvjGGP9T1kF6k3VW0s0HgvzgkJZidAjrZ4jaTRqR/djU EI9Q== X-Gm-Message-State: ANhLgQ0spFWNsjPJDbVbrkGIHsl93nbCvseQB8OA2lq+cOR5zFMaicoj YKeNUnTh2kdX6mQd8YQRrI1HxA== X-Google-Smtp-Source: ADFU+vs1cY0h+g/ybHd7aq9aAE2q7J9qQbOvmeUgc6gSXldSzXKDqGGuNEQYYStflkny8WIXLgRMYQ== X-Received: by 2002:a1c:7711:: with SMTP id t17mr2772854wmi.108.1584613113335; Thu, 19 Mar 2020 03:18:33 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id n1sm2723582wrj.77.2020.03.19.03.18.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Mar 2020 03:18:32 -0700 (PDT) Date: Thu, 19 Mar 2020 11:18:30 +0100 From: Daniel Vetter To: Greg KH Cc: Daniel Vetter , Wambui Karuga , Dave Airlie , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , dri-devel , Linux Kernel Mailing List Subject: Re: [PATCH v2 10/17] drm/vram-helper: make drm_vram_mm_debugfs_init() return 0 Message-ID: <20200319101830.GB2363188@phenom.ffwll.local> Mail-Followup-To: Greg KH , Wambui Karuga , Dave Airlie , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , dri-devel , Linux Kernel Mailing List References: <20200310133121.27913-1-wambui.karugax@gmail.com> <20200310133121.27913-11-wambui.karugax@gmail.com> <20200318152627.GY2363188@phenom.ffwll.local> <20200318165846.GC3090655@kroah.com> <20200319075524.GB3445010@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200319075524.GB3445010@kroah.com> X-Operating-System: Linux phenom 5.3.0-3-amd64 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 19, 2020 at 08:55:24AM +0100, Greg KH wrote: > On Wed, Mar 18, 2020 at 08:10:43PM +0100, Daniel Vetter wrote: > > On Wed, Mar 18, 2020 at 5:58 PM Greg KH wrote: > > > > > > On Wed, Mar 18, 2020 at 05:31:47PM +0100, Daniel Vetter wrote: > > > > On Wed, Mar 18, 2020 at 5:03 PM Wambui Karuga wrote: > > > > > > > > > > > > > > > > > > > > On Wed, 18 Mar 2020, Daniel Vetter wrote: > > > > > > > > > > > On Tue, Mar 10, 2020 at 04:31:14PM +0300, Wambui Karuga wrote: > > > > > >> Since 987d65d01356 (drm: debugfs: make > > > > > >> drm_debugfs_create_files() never fail), drm_debugfs_create_files() never > > > > > >> fails and should return void. Therefore, remove its use as the > > > > > >> return value of drm_vram_mm_debugfs_init(), and have the function > > > > > >> return 0 directly. > > > > > >> > > > > > >> v2: have drm_vram_mm_debugfs_init() return 0 instead of void to avoid > > > > > >> introducing build issues and build breakage. > > > > > >> > > > > > >> References: https://lists.freedesktop.org/archives/dri-devel/2020-February/257183.html > > > > > >> Signed-off-by: Wambui Karuga > > > > > >> Acked-by: Thomas Zimmermann > > > > > >> --- > > > > > >> drivers/gpu/drm/drm_gem_vram_helper.c | 10 ++++------ > > > > > >> 1 file changed, 4 insertions(+), 6 deletions(-) > > > > > >> > > > > > >> diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c > > > > > >> index 92a11bb42365..c8bcc8609650 100644 > > > > > >> --- a/drivers/gpu/drm/drm_gem_vram_helper.c > > > > > >> +++ b/drivers/gpu/drm/drm_gem_vram_helper.c > > > > > >> @@ -1048,14 +1048,12 @@ static const struct drm_info_list drm_vram_mm_debugfs_list[] = { > > > > > >> */ > > > > > >> int drm_vram_mm_debugfs_init(struct drm_minor *minor) > > > > > >> { > > > > > >> - int ret = 0; > > > > > >> - > > > > > >> #if defined(CONFIG_DEBUG_FS) > > > > > > > > > > > > Just noticed that this #if here is not needed, we already have a dummy > > > > > > function for that case. Care to write a quick patch to remove it? On top > > > > > > of this patch series here ofc, I'm in the processing of merging the entire > > > > > > pile. > > > > > > > > > > > > Thanks, Daniel > > > > > Hi Daniel, > > > > > Without this check here, and compiling without CONFIG_DEBUG_FS, this > > > > > function is run and the drm_debugfs_create_files() does not have access to > > > > > the parameters also protected by an #if above this function. So the change > > > > > throws an error for me. Is that correct? > > > > > > > > Hm right. Other drivers don't #ifdef out their debugfs file functions > > > > ... kinda a bit disappointing that we can't do this in the neatest way > > > > possible. > > > > > > > > Greg, has anyone ever suggested to convert the debugfs_create_file > > > > function (and similar things) to macros that don't use any of the > > > > arguments, and then also annotating all the static functions/tables as > > > > __maybe_unused and let the compiler garbage collect everything? > > > > Instead of explicit #ifdef in all the drivers ... > > > > > > No, no one has suggested that, having the functions be static inline > > > should make it all "just work" properly if debugfs is not enabled. The > > > variables will not be used, so the compiler should just optimize them > > > away properly. > > > > > > No checks for CONFIG_DEBUG_FS should be needed anywhere in .c code. > > > > So the trouble with this one is that the static inline functions for > > the debugfs file are wrapped in a #if too, and hence if we drop the > > #if around the function call stuff won't compile. Should we drop all > > the #if in the .c file and assume the compiler will remove all the > > dead code and dead functions? > > Yes you should :) > > there should not be any need for #if in a .c file for debugfs stuff. Wambui, can you pls try that out? I.e. removing all the #if for CONFIG_DEBUG_FS from that file. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch