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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, USER_AGENT_GIT 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 CBD74C43381 for ; Wed, 27 Mar 2019 19:28:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C9002075E for ; Wed, 27 Mar 2019 19:28:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553714933; bh=PS9cLOtuEHtVrC6GCM+3U4hVfZYr9gBjv0rFFMGxhio=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SHrOVgwnP5qG0F6rs9S4kkiL4ypTerZO+temcpaJuxzgotBNmkoQGnyA6lRQ313Er b+IOmARolwZu2gTNHZO0C/U6IAs/FS/CEVjGqphopzWr0goB6vjPIVocswfZHybkXs eZJNBmgJhNbBr6JvgpAqwPmgJBbetKMsatLuV5GI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733153AbfC0SEK (ORCPT ); Wed, 27 Mar 2019 14:04:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:44664 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733148AbfC0SEG (ORCPT ); Wed, 27 Mar 2019 14:04:06 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E160E2063F; Wed, 27 Mar 2019 18:04:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553709845; bh=PS9cLOtuEHtVrC6GCM+3U4hVfZYr9gBjv0rFFMGxhio=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YsaHK2ICNwF2Gc9G4ZSxU/M7eFvge+QjAPjSuPN2z3SCsVUOslSf832wBL+djO0zK iyJD2C1QX1ZCXxmHP6mGlEhOpFxheODPEL3hgfWKebYRp7GXF+Bf3APXtZyMlSjvpo pHYiP0LXHSV/X5FVd8tsDPiekman9vqjt3He8E3Y= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nathan Chancellor , Alex Deucher , Sasha Levin , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.0 070/262] drm/amd/display: Pass app_tf by value rather than by reference Date: Wed, 27 Mar 2019 13:58:45 -0400 Message-Id: <20190327180158.10245-70-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190327180158.10245-1-sashal@kernel.org> References: <20190327180158.10245-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nathan Chancellor [ Upstream commit 672e78cab819ebe31e3b9b8abac367be8a110472 ] Clang warns when an expression that equals zero is used as a null pointer constant (in lieu of NULL): drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:4435:3: warning: expression which evaluates to zero treated as a null pointer constant of type 'const enum color_transfer_func *' [-Wnon-literal-null-conversion] TRANSFER_FUNC_UNKNOWN, ^~~~~~~~~~~~~~~~~~~~~ 1 warning generated. This warning is caused by commit bb47de736661 ("drm/amdgpu: Set FreeSync state using drm VRR properties") and it could be solved by using NULL instead of TRANSFER_FUNC_UNKNOWN or casting TRANSFER_FUNC_UNKNOWN as a pointer. However, after looking into it, there doesn't appear to be a good reason to pass app_tf by reference as it is never mutated along the way. This is the only code path in which app_tf is used: mod_freesync_build_vrr_infopacket -> build_vrr_infopacket_v2 -> build_vrr_infopacket_fs2_data Neither mod_freesync_build_vrr_infopacket or build_vrr_infopacket_v2 modify app_tf's value and build_vrr_infopacket_fs2_data expects just the value so we can avoid dereferencing anything by just passing in app_tf's value to mod_freesync_build_vrr_infopacket and build_vrr_infopacket_v2. There is no functional change because build_vrr_infopacket_fs2_data doesn't do anything if TRANSFER_FUNC_UNKNOWN is passed to it, the same as not calling build_vrr_infopacket_fs2_data at all like before this change when NULL was used for app_tf. Reviewed-by: Harry Wentland Signed-off-by: Nathan Chancellor Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/modules/freesync/freesync.c | 7 +++---- drivers/gpu/drm/amd/display/modules/inc/mod_freesync.h | 2 +- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c index 1544ed3f1747..945e845f3358 100644 --- a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c +++ b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c @@ -656,7 +656,7 @@ static void build_vrr_infopacket_v1(enum signal_type signal, static void build_vrr_infopacket_v2(enum signal_type signal, const struct mod_vrr_params *vrr, - const enum color_transfer_func *app_tf, + enum color_transfer_func app_tf, struct dc_info_packet *infopacket) { unsigned int payload_size = 0; @@ -664,8 +664,7 @@ static void build_vrr_infopacket_v2(enum signal_type signal, build_vrr_infopacket_header_v2(signal, infopacket, &payload_size); build_vrr_infopacket_data(vrr, infopacket); - if (app_tf != NULL) - build_vrr_infopacket_fs2_data(*app_tf, infopacket); + build_vrr_infopacket_fs2_data(app_tf, infopacket); build_vrr_infopacket_checksum(&payload_size, infopacket); @@ -676,7 +675,7 @@ void mod_freesync_build_vrr_infopacket(struct mod_freesync *mod_freesync, const struct dc_stream_state *stream, const struct mod_vrr_params *vrr, enum vrr_packet_type packet_type, - const enum color_transfer_func *app_tf, + enum color_transfer_func app_tf, struct dc_info_packet *infopacket) { /* SPD info packet for FreeSync */ diff --git a/drivers/gpu/drm/amd/display/modules/inc/mod_freesync.h b/drivers/gpu/drm/amd/display/modules/inc/mod_freesync.h index 949a8b62aa98..063af6258fd9 100644 --- a/drivers/gpu/drm/amd/display/modules/inc/mod_freesync.h +++ b/drivers/gpu/drm/amd/display/modules/inc/mod_freesync.h @@ -145,7 +145,7 @@ void mod_freesync_build_vrr_infopacket(struct mod_freesync *mod_freesync, const struct dc_stream_state *stream, const struct mod_vrr_params *vrr, enum vrr_packet_type packet_type, - const enum color_transfer_func *app_tf, + enum color_transfer_func app_tf, struct dc_info_packet *infopacket); void mod_freesync_build_vrr_params(struct mod_freesync *mod_freesync, -- 2.19.1