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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 01D2BC10DCE for ; Fri, 6 Mar 2020 23:49:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF2D620709 for ; Fri, 6 Mar 2020 23:49:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JQIXSOMh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727639AbgCFXtn (ORCPT ); Fri, 6 Mar 2020 18:49:43 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:36706 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727605AbgCFXtd (ORCPT ); Fri, 6 Mar 2020 18:49:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583538572; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=77mV7dMChSrLWq5rIbMFOAlvL63d0ZbvZ9seihNouTU=; b=JQIXSOMhPJgYyH558fmTXQI6gBk4bVfqnCZ5KRYOK+mPzl6t8ht+Rdd1T7RyncyOj5eSwZ dxyvF5rv/yTJzhi+kaMQOURlDCljNfj9oWlD+bLyLeRCaMgkJGGzM9QGWL+2hywoGCpGRD aLAqtCSHdJ6iH7srJpA3vabWjU2U1/E= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-8-G7T3Kw1sPsy-SN61B098Vw-1; Fri, 06 Mar 2020 18:49:30 -0500 X-MC-Unique: G7T3Kw1sPsy-SN61B098Vw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2FBA51005509; Fri, 6 Mar 2020 23:49:29 +0000 (UTC) Received: from Ruby.bss.redhat.com (dhcp-10-20-1-196.bss.redhat.com [10.20.1.196]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2D58591D9D; Fri, 6 Mar 2020 23:49:28 +0000 (UTC) From: Lyude Paul To: dri-devel@lists.freedesktop.org Cc: Benjamin Gaignard , Sean Paul , Hans de Goede , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , linux-kernel@vger.kernel.org Subject: [PATCH 2/2] drm/dp_mst: Fix drm_dp_check_mstb_guid() return code Date: Fri, 6 Mar 2020 18:49:22 -0500 Message-Id: <20200306234923.547873-3-lyude@redhat.com> In-Reply-To: <20200306234923.547873-1-lyude@redhat.com> References: <20200306234923.547873-1-lyude@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We actually expect this to return a 0 on success, or negative error code on failure. In order to do that, we check whether or not we managed to write the whole GUID and then return 0 if so, otherwise return a negative error code. Also, let's add an error message here so it's a little more obvious when this fails in the middle of a link address probe. This should fix issues with certain MST hubs seemingly stopping for no reason in the middle of the link address probe process. Fixes: cb897542c6d2 ("drm/dp_mst: Fix W=3D1 warnings") Cc: Benjamin Gaignard Cc: Sean Paul Cc: Hans de Goede Signed-off-by: Lyude Paul --- drivers/gpu/drm/drm_dp_mst_topology.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_= dp_mst_topology.c index e421c2d13267..b2ec6e8634ed 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2092,7 +2092,10 @@ static int drm_dp_check_mstb_guid(struct drm_dp_ms= t_branch *mstb, u8 *guid) } } =20 - return ret; + if (ret < 16 && ret > 0) + return -EPROTO; + + return ret =3D=3D 16 ? 0 : ret; } =20 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, @@ -2907,8 +2910,14 @@ static int drm_dp_send_link_address(struct drm_dp_= mst_topology_mgr *mgr, drm_dp_dump_link_address(reply); =20 ret =3D drm_dp_check_mstb_guid(mstb, reply->guid); - if (ret) + if (ret) { + char buf[64]; + + drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf)); + DRM_ERROR("GUID check on %s failed: %d\n", + buf, ret); goto out; + } =20 for (i =3D 0; i < reply->nports; i++) { port_mask |=3D BIT(reply->ports[i].port_number); --=20 2.24.1