From nobody Fri Dec 19 17:23:23 2025 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 7D58DC38A2D for ; Mon, 24 Oct 2022 13:11:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235634AbiJXNLy (ORCPT ); Mon, 24 Oct 2022 09:11:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235640AbiJXNJM (ORCPT ); Mon, 24 Oct 2022 09:09:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 746539F749; Mon, 24 Oct 2022 05:22:18 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 07850612E7; Mon, 24 Oct 2022 12:22:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AD4EC433D6; Mon, 24 Oct 2022 12:22:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666614137; bh=NDhl75XBw/Cv2H9f1biVIkMHuvFLt/dll9cekvRZ4cs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rNNbYes0EXswXmS5zp6xT7jKI8/VrBc73LHtlQh0xbSd+Xqng3L1Hlhfr/L2l0ma4 npkSbUsNyTZTaSk4z2vVEk36Chgr+D8g0S9ewkVdq/6rmW5VWdZRFqQ3MrruOursci i1URHsWo3P1X0ADZmDItOVxE4RVtgdqmgQde2zpk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Simon Ser , Lyude Paul , Benjamin Gaignard , Jani Nikula , Sasha Levin Subject: [PATCH 5.10 145/390] drm/dp_mst: fix drm_dp_dpcd_read return value checks Date: Mon, 24 Oct 2022 13:29:02 +0200 Message-Id: <20221024113028.858350468@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024113022.510008560@linuxfoundation.org> References: <20221024113022.510008560@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Simon Ser [ Upstream commit 2ac6cdd581f48c8f68747156fde5868486a44985 ] drm_dp_dpcd_read returns the number of bytes read. The previous code would print garbage on DPCD error, and would exit with on error on success. Signed-off-by: Simon Ser Fixes: cb897542c6d2 ("drm/dp_mst: Fix W=3D1 warnings") Cc: Lyude Paul Cc: Benjamin Gaignard Reviewed-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/473500/ Signed-off-by: Sasha Levin --- drivers/gpu/drm/drm_dp_mst_topology.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp= _mst_topology.c index ab423b0413ee..4272cd3622f8 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -4856,14 +4856,14 @@ void drm_dp_mst_dump_topology(struct seq_file *m, seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf); =20 ret =3D drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2); - if (ret) { + if (ret !=3D 2) { seq_printf(m, "faux/mst read failed\n"); goto out; } seq_printf(m, "faux/mst: %*ph\n", 2, buf); =20 ret =3D drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1); - if (ret) { + if (ret !=3D 1) { seq_printf(m, "mst ctrl read failed\n"); goto out; } @@ -4871,7 +4871,7 @@ void drm_dp_mst_dump_topology(struct seq_file *m, =20 /* dump the standard OUI branch header */ ret =3D drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEA= DER_SIZE); - if (ret) { + if (ret !=3D DP_BRANCH_OUI_HEADER_SIZE) { seq_printf(m, "branch oui read failed\n"); goto out; } --=20 2.35.1