From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:60799 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752677AbcEAXVP (ORCPT ); Sun, 1 May 2016 19:21:15 -0400 Subject: Patch "drm/dp/mst: Restore primary hub guid on resume" has been added to the 4.4-stable tree To: cpaul@redhat.com, airlied@redhat.com, daniel.vetter@ffwll.ch, gregkh@linuxfoundation.org, harry.wentland@amd.com Cc: , From: Date: Sun, 01 May 2016 16:21:14 -0700 Message-ID: <146214487411069@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled drm/dp/mst: Restore primary hub guid on resume to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-dp-mst-restore-primary-hub-guid-on-resume.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 9dc0487d96a0396367a1451b31873482080b527f Mon Sep 17 00:00:00 2001 From: Lyude Date: Wed, 13 Apr 2016 16:50:18 -0400 Subject: drm/dp/mst: Restore primary hub guid on resume From: Lyude commit 9dc0487d96a0396367a1451b31873482080b527f upstream. Some hubs are forgetful, and end up forgetting whatever GUID we set previously after we do a suspend/resume cycle. This can lead to hotplugging breaking (along with probably other things) since the hub will start sending connection notifications with the wrong GUID. As such, we need to check on resume whether or not the GUID the hub is giving us is valid. Signed-off-by: Lyude Reviewed-by: Harry Wentland Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1460580618-7421-1-git-send-email-cpaul@redhat.com Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_dp_mst_topology.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2116,6 +2116,8 @@ int drm_dp_mst_topology_mgr_resume(struc if (mgr->mst_primary) { int sret; + u8 guid[16]; + sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE); if (sret != DP_RECEIVER_CAP_SIZE) { DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n"); @@ -2130,6 +2132,16 @@ int drm_dp_mst_topology_mgr_resume(struc ret = -1; goto out_unlock; } + + /* Some hubs forget their guids after they resume */ + sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16); + if (sret != 16) { + DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n"); + ret = -1; + goto out_unlock; + } + drm_dp_check_mstb_guid(mgr->mst_primary, guid); + ret = 0; } else ret = -1; Patches currently in stable-queue which might be from cpaul@redhat.com are queue-4.4/drm-dp-mst-restore-primary-hub-guid-on-resume.patch queue-4.4/drm-dp-mst-validate-port-in-drm_dp_payload_send_msg.patch queue-4.4/drm-i915-fix-race-condition-in-intel_dp_destroy_mst_connector.patch queue-4.4/drm-dp-mst-get-validated-port-ref-in-drm_dp_update_payload_part1.patch