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 12623C433F5 for ; Mon, 10 Oct 2022 00:21:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230391AbiJJAVt (ORCPT ); Sun, 9 Oct 2022 20:21:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232481AbiJJAUD (ORCPT ); Sun, 9 Oct 2022 20:20:03 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1090DE1E; Sun, 9 Oct 2022 16:54:41 -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 ams.source.kernel.org (Postfix) with ESMTPS id 459AFB80D33; Sun, 9 Oct 2022 23:54:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8395CC433C1; Sun, 9 Oct 2022 23:54:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1665359679; bh=IqXIc2zb1gPqjZAiZAuDXqBufstMjobSxTTlD79UXjo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PgDCXAABSZm7wXIWUF6R9+jwyIZNuDvpUzCG/BH3b2wdVs28L5mFKWItnPDxFiL8e 7AewTnS70oEEbikvZ4KJ/AozFhd5anDoyaEpxLsIeO1bS5Nyqzq/0GbRxsDgcQf0A1 9vxBLA8kGAVegD+WGB5uqRI6puYfUJ+j/4Ilgncqr+TVAQJj8iccQMrDytltzpd8U4 xXd600rxs1WJaDt/ht4GS1xDCNg7plNi+E8wGfYmCnS43LWCX/0EHeGFk4hD0A+Dd7 BRv376MFaBE0u/DgERAcJenf4BF2tipzrYBOLhh6VT3DHmitM2j+2kB/8wIYMa8bTG ztbt8Tadr5mHQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Gow , Tales Aparecida , Alex Deucher , Sasha Levin , harry.wentland@amd.com, sunpeng.li@amd.com, Rodrigo.Siqueira@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@gmail.com, daniel@ffwll.ch, isabbasso@riseup.net, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.15 06/25] drm/amd/display: fix overflow on MIN_I64 definition Date: Sun, 9 Oct 2022 19:54:06 -0400 Message-Id: <20221009235426.1231313-6-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221009235426.1231313-1-sashal@kernel.org> References: <20221009235426.1231313-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore 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