From nobody Sun Feb 8 21:46:32 2026 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 2BF0BC4332F for ; Wed, 19 Oct 2022 09:03:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232290AbiJSJDM (ORCPT ); Wed, 19 Oct 2022 05:03:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232265AbiJSJBf (ORCPT ); Wed, 19 Oct 2022 05:01:35 -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 C61AC8E0E8; Wed, 19 Oct 2022 01:55:52 -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 8EA13617E8; Wed, 19 Oct 2022 08:54:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A164FC433D6; Wed, 19 Oct 2022 08:54:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666169656; bh=C1rwG8z2GfL29LvFgqELgKitE9ciVJlqDiNdRtp24lY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uskLR9PpRwBmdDUryxzBYZrn1AgMU2WmV2Ly73iF9bFE4BeedQ9yDKkBayLBZ4ZqH 75Ngbqi+reJWgWbThZhOUdmOf/gkASwFIfKVjpW4gfs2LCV4Hi/pU5Q65ZfAik2aLg nxTcRKQCoPNkwyJhlouwad8wVycDPN+UXv4aNOcw= 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 6.0 358/862] drm/dp_mst: fix drm_dp_dpcd_read return value checks Date: Wed, 19 Oct 2022 10:27:25 +0200 Message-Id: <20221019083305.822247722@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221019083249.951566199@linuxfoundation.org> References: <20221019083249.951566199@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/display/drm_dp_mst_topology.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/dr= m/display/drm_dp_mst_topology.c index 57e65423e50d..7a94a5288e8d 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -4907,14 +4907,14 @@ 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; } @@ -4922,7 +4922,7 @@ 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