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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 DEE3AC4338F for ; Thu, 19 Aug 2021 17:18:32 +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 79E3061028 for ; Thu, 19 Aug 2021 17:18:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 79E3061028 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ravnborg.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AFCA36E9B5; Thu, 19 Aug 2021 17:18:31 +0000 (UTC) Received: from mx1.smtp.larsendata.com (mx1.smtp.larsendata.com [91.221.196.215]) by gabe.freedesktop.org (Postfix) with ESMTPS id 162F76E9B5 for ; Thu, 19 Aug 2021 17:18:29 +0000 (UTC) Received: from mail01.mxhotel.dk (mail01.mxhotel.dk [91.221.196.236]) by mx1.smtp.larsendata.com (Halon) with ESMTPS id 72690443-0111-11ec-b37b-0050568c148b; Thu, 19 Aug 2021 17:18:18 +0000 (UTC) Received: from ravnborg.org (80-162-45-141-cable.dk.customer.tdc.net [80.162.45.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: sam@ravnborg.org) by mail01.mxhotel.dk (Postfix) with ESMTPSA id 75BA7194B17; Thu, 19 Aug 2021 19:18:38 +0200 (CEST) Date: Thu, 19 Aug 2021 19:18:25 +0200 X-Report-Abuse-To: abuse@mxhotel.dk From: Sam Ravnborg To: Colin King Cc: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/bridge/tc358767: make the array ext_div static const, makes object smaller Message-ID: References: <20210819133839.10745-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210819133839.10745-1-colin.king@canonical.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Colin, On Thu, Aug 19, 2021 at 02:38:39PM +0100, Colin King wrote: > From: Colin Ian King > > Don't populate the array ext_div on the stack but instead it > static const. Makes the object code smaller by 118 bytes: > > Before: > text data bss dec hex filename > 39449 17500 128 57077 def5 ./drivers/gpu/drm/bridge/tc358767.o > > After: > text data bss dec hex filename > 39235 17596 128 56959 de7f ./drivers/gpu/drm/bridge/tc358767.o > > (gcc version 10.3.0) IMO a better argument is that this change prevents any accidental changes and it align with how we define arrays in many other places. The compiler may produce a smaller binary but that is just a side-effect in this case. Sam > > Signed-off-by: Colin Ian King > --- > drivers/gpu/drm/bridge/tc358767.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c > index 23a6f90b694b..599c23759400 100644 > --- a/drivers/gpu/drm/bridge/tc358767.c > +++ b/drivers/gpu/drm/bridge/tc358767.c > @@ -468,7 +468,7 @@ static int tc_pxl_pll_en(struct tc_data *tc, u32 refclk, u32 pixelclock) > int div, best_div = 1; > int mul, best_mul = 1; > int delta, best_delta; > - int ext_div[] = {1, 2, 3, 5, 7}; > + static const int ext_div[] = {1, 2, 3, 5, 7}; > int best_pixelclock = 0; > int vco_hi = 0; > u32 pxl_pllparam; > -- > 2.32.0