From nobody Wed Dec 17 13:45:26 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 72AD1C77B73 for ; Wed, 19 Apr 2023 11:25:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231580AbjDSLZI (ORCPT ); Wed, 19 Apr 2023 07:25:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232711AbjDSLZB (ORCPT ); Wed, 19 Apr 2023 07:25:01 -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 75EA07A9B for ; Wed, 19 Apr 2023 04:24:50 -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 06CA661524 for ; Wed, 19 Apr 2023 11:24:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9FC3AC433EF; Wed, 19 Apr 2023 11:24:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681903489; bh=PanmDTu5lRIgSn8GKJ9uoLf6Evo6osxCZ4efcHlSt3U=; h=From:To:Cc:Subject:Date:From; b=iWQ76DyFPVUXh4v11hmPber04xI849i4omW2/7EpTyHlfQDeFGzMNdfmt/ptO7kEL Uj9fIK7xlz6KlyMtCZstTGAlwRevPS5u8I2hHOsbzqk6F1kIhcKYdcTlGY5bGwF6T/ udu4HtrAfP/zvSChXI+Y4wOJ+6HPJDr0L32KI+1AfW2mspcd+mqXM0cQgyIaWEVCcF JODgl1mC7L1n3tsOOOG9mTMwukBNITvN7ANRt3v8hI9dhTFeidy2nYOOKjYBevJzHH WPoFWj41GmJQdCTm5w+jN8IBCbM7NFwqL51yEahYRBtJSm4zE5NvL4+XDU9YtanTWI FlKc3OmIggNRw== From: Jeff Layton To: David Airlie , Daniel Vetter Cc: Wayne.Lin@amd.com, lyude@redhat.com, alexdeucher@gmail.com, Jani Nikula , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] drm: use mgr->dev in drm_dbg_kms in drm_dp_add_payload_part2 Date: Wed, 19 Apr 2023 07:24:46 -0400 Message-Id: <20230419112447.18471-1-jlayton@kernel.org> X-Mailer: git-send-email 2.39.2 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" I've been experiencing some intermittent crashes down in the display driver code. The symptoms are ususally a line like this in dmesg: amdgpu 0000:30:00.0: [drm] Failed to create MST payload for port 000000= 006d3a3885: -5 ...followed by an Oops due to a NULL pointer dereference. Switch to using mgr->dev instead of state->dev since "state" can be NULL in some cases. Link: https://bugzilla.redhat.com/show_bug.cgi?id=3D2184855 Suggested-by: Jani Nikula Signed-off-by: Jeff Layton Reviewed-by: Jani Nikula Reviewed-by: Lyude Paul --- drivers/gpu/drm/display/drm_dp_mst_topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) I've been running this patch for a couple of days, but the problem hasn't occurred again as of yet. It seems sane though as long as we can assume that mgr->dev will be valid even when "state" is a NULL pointer. diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/dr= m/display/drm_dp_mst_topology.c index 38dab76ae69e..e2e21ce79510 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -3404,7 +3404,7 @@ int drm_dp_add_payload_part2(struct drm_dp_mst_topolo= gy_mgr *mgr, =20 /* Skip failed payloads */ if (payload->vc_start_slot =3D=3D -1) { - drm_dbg_kms(state->dev, "Part 1 of payload creation for %s failed, skipp= ing part 2\n", + drm_dbg_kms(mgr->dev, "Part 1 of payload creation for %s failed, skippin= g part 2\n", payload->port->connector->name); return -EIO; } --=20 2.39.2