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 9C67DC67871 for ; Mon, 24 Oct 2022 20:14:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234014AbiJXUOo (ORCPT ); Mon, 24 Oct 2022 16:14:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230111AbiJXUNv (ORCPT ); Mon, 24 Oct 2022 16:13:51 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A56717E837; Mon, 24 Oct 2022 11:32:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 3178BCE16F2; Mon, 24 Oct 2022 12:52:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 450CAC433D6; Mon, 24 Oct 2022 12:52:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666615960; bh=IqXIc2zb1gPqjZAiZAuDXqBufstMjobSxTTlD79UXjo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NpU+n8hjn35o3HcueK+tgedoU5AolUBBS2802GKIyIncPE+l7P+kkBLfcVYXgC0Oe x/d9sgNugL0AL/2php1JhK0UcyOLZzG9t7TaHi/BImLVl56Q7i34gCDM0vgfzrNsfb rFSoZz84zqdrvxIkzYwWUvN0FxH1M59F6+gIZ+4s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Gow , Tales Aparecida , Alex Deucher , Sasha Levin Subject: [PATCH 5.15 448/530] drm/amd/display: fix overflow on MIN_I64 definition Date: Mon, 24 Oct 2022 13:33:12 +0200 Message-Id: <20221024113105.320201108@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024113044.976326639@linuxfoundation.org> References: <20221024113044.976326639@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Gow [ Upstream commit 6ae0632d17759852c07e2d1e0a31c728eb6ba246 ] The definition of MIN_I64 in bw_fixed.c can cause gcc to whinge about integer overflow, because it is treated as a positive value, which is then negated. The temporary positive value is not necessarily representable. This causes the following warning: ../drivers/gpu/drm/amd/amdgpu/../display/dc/dml/calcs/bw_fixed.c:30:19: warning: integer overflow in expression ‘-9223372036854775808’ of type ‘long long int’ results in ‘-9223372036854775808’ [-Woverflow] 30 | (int64_t)(-(1LL << 63)) | ^ Writing out (-MAX_I64 - 1) works instead. Signed-off-by: David Gow Signed-off-by: Tales Aparecida Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c b/drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c index 6ca288fb5fb9..2d46bc527b21 100644 --- a/drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c +++ b/drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c @@ -26,12 +26,12 @@ #include "bw_fixed.h" -#define MIN_I64 \ - (int64_t)(-(1LL << 63)) - #define MAX_I64 \ (int64_t)((1ULL << 63) - 1) +#define MIN_I64 \ + (-MAX_I64 - 1) + #define FRACTIONAL_PART_MASK \ ((1ULL << BW_FIXED_BITS_PER_FRACTIONAL_PART) - 1) -- 2.35.1