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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 82FC1C433F5 for ; Mon, 7 Feb 2022 19:49:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240973AbiBGTr2 (ORCPT ); Mon, 7 Feb 2022 14:47:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240575AbiBGTpI (ORCPT ); Mon, 7 Feb 2022 14:45:08 -0500 Received: from mail-lj1-x22e.google.com (mail-lj1-x22e.google.com [IPv6:2a00:1450:4864:20::22e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BDA6C0401E0 for ; Mon, 7 Feb 2022 11:45:07 -0800 (PST) Received: by mail-lj1-x22e.google.com with SMTP id u7so19687180lji.2 for ; Mon, 07 Feb 2022 11:45:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=lZDpDADdfwq40jZPbE/sznh7Bnymle3eu2MsiKyAnHI=; b=BdiDafPxAfgT1LadX6/qdSNo8n3l0Xa/GtCJEktDJMXEmp52SrE42F60zh+yNtgnej uafnZUT8MJqOawyMYksVSqsD8w5zXATUGodDDaf2n0OSYIP77vOHkN1WwPFv0stLOa78 +4ATpfopW4dS5hdH2p54SyosNF1m7zjr8r+2YE4GWs0neqc92bzF3dIJD7hE8cA0PJPs kQu1XjE348Lq3znmdTjfrSq9FD04iuxmobdD48LoM7k4xW51/uiPDMkZVxL359FVEki8 6hN3NzqdifRAShPzrX73QDVc8Pe4IH8JQaohdbJyNHzgPOa0p/tQFkgSdDhkiO0KiTmj Kknw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=lZDpDADdfwq40jZPbE/sznh7Bnymle3eu2MsiKyAnHI=; b=7oGjJUIgFQyAcTPDXBuQpO1x+0P+4hMCtzxw6thuD+eNwkrKma++Uo5lX5QB9HjMwJ a/UHy+llEnqUcHmmvvJ2NGMiSb78KhmS7iJYQOJ6drf6GFeHiR38CWa059p+LXOhy81W eFjMSnJAOpchJurpkOvWmhr73YAqa/jVLZpZR8knAwUwavAHRLcEoZNWYSqkM5ZZGD5w UMixDNpH4C8qPbG1BiAsDrIR3F0nwcyadgIbGsGOappwqfhsqT3wzUIdjTjLgx1rRjqn KoVMWH7YGnFaMCCGKKUzqapGd/ge56WJuz1BovoQ7tm84/Jk3AF1RrCaFMcxdobkgGji qwjA== X-Gm-Message-State: AOAM532VnRiJS2Y9hZEQn7F9Ddkmz2Ss6QRuYEBg/3gWC5Ul9p68LlQb WZHUuv4fKw7j9AXMxjhmNFur1jt1FbYF7lL623wc5A== X-Google-Smtp-Source: ABdhPJwv1WF2F6ndc/bGUuNT+neSxWAOv6iXkCytc6pktYWRpfycPf6E/KpzZmQrd8aUu/NlJ8No19+iCvFMptVtXu4= X-Received: by 2002:a2e:7c0c:: with SMTP id x12mr648215ljc.526.1644263105665; Mon, 07 Feb 2022 11:45:05 -0800 (PST) MIME-Version: 1.0 References: <20220207165304.1046867-1-nathan@kernel.org> In-Reply-To: <20220207165304.1046867-1-nathan@kernel.org> From: Nick Desaulniers Date: Mon, 7 Feb 2022 11:44:53 -0800 Message-ID: Subject: Re: [PATCH] drm/stm: Avoid using val uninitialized in ltdc_set_ycbcr_config() To: Nathan Chancellor Cc: Yannick Fertre , Philippe Cornu , Benjamin Gaignard , dri-devel@lists.freedesktop.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 7, 2022 at 8:53 AM Nathan Chancellor wrote: > > Clang warns: > > drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized] > default: > ^~~~~~~ > drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here > val |= LxPCR_YCEN; > ^~~ > drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning > u32 val; > ^ > = 0 > 1 warning generated. > > Use a return instead of break in the default case to fix the warning. > Add an error message so that this return is not silent, which could hide > issues in the future. > > Fixes: 484e72d3146b ("drm/stm: ltdc: add support of ycbcr pixel formats") > Link: https://github.com/ClangBuiltLinux/linux/issues/1575 > Signed-off-by: Nathan Chancellor > --- > drivers/gpu/drm/stm/ltdc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c > index 5eeb32c9c9ce..447ddde1786c 100644 > --- a/drivers/gpu/drm/stm/ltdc.c > +++ b/drivers/gpu/drm/stm/ltdc.c > @@ -624,7 +624,8 @@ static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fm > break; > default: > /* RGB or not a YCbCr supported format */ > - break; > + drm_err(plane->dev, "Unsupported pixel format: %u\n", drm_pix_fmt); This is fine, but in the future you should add an explicit #include to avoid implicit header dependencies (like the ones that Mingo is trying to detangle) for the declaration of drm_err. `drm_vprintf` needs it, too. Reviewed-by: Nick Desaulniers > + return; > } > > /* Enable limited range */ > > base-commit: 542898c5aa5c6a3179dffb1d1606884a63f75fed > -- > 2.35.1 > -- Thanks, ~Nick Desaulniers