| From 35d3e8cb35e75450f87f87e3d314e2d418b6954b Mon Sep 17 00:00:00 2001 |
| From: Wayne Lin <Wayne.Lin@amd.com> |
| Date: Wed, 16 Jun 2021 11:55:00 +0800 |
| Subject: drm/dp_mst: Do not set proposed vcpi directly |
| |
| From: Wayne Lin <Wayne.Lin@amd.com> |
| |
| commit 35d3e8cb35e75450f87f87e3d314e2d418b6954b upstream. |
| |
| [Why] |
| When we receive CSN message to notify one port is disconnected, we will |
| implicitly set its corresponding num_slots to 0. Later on, we will |
| eventually call drm_dp_update_payload_part1() to arrange down streams. |
| |
| In drm_dp_update_payload_part1(), we iterate over all proposed_vcpis[] |
| to do the update. Not specific to a target sink only. For example, if we |
| light up 2 monitors, Monitor_A and Monitor_B, and then we unplug |
| Monitor_B. Later on, when we call drm_dp_update_payload_part1() to try |
| to update payload for Monitor_A, we'll also implicitly clean payload for |
| Monitor_B at the same time. And finally, when we try to call |
| drm_dp_update_payload_part1() to clean payload for Monitor_B, we will do |
| nothing at this time since payload for Monitor_B has been cleaned up |
| previously. |
| |
| For StarTech 1to3 DP hub, it seems like if we didn't update DPCD payload |
| ID table then polling for "ACT Handled"(BIT_1 of DPCD 002C0h) will fail |
| and this polling will last for 3 seconds. |
| |
| Therefore, guess the best way is we don't set the proposed_vcpi[] |
| diretly. Let user of these herlper functions to set the proposed_vcpi |
| directly. |
| |
| [How] |
| 1. Revert commit 7617e9621bf2 ("drm/dp_mst: clear time slots for ports |
| invalid") |
| 2. Tackle the issue in previous commit by skipping those trasient |
| proposed VCPIs. These stale VCPIs shoulde be explicitly cleared by |
| user later on. |
| |
| Changes since v1: |
| * Change debug macro to use drm_dbg_kms() instead |
| * Amend the commit message to add Fixed & Cc tags |
| |
| Signed-off-by: Wayne Lin <Wayne.Lin@amd.com> |
| Fixes: 7617e9621bf2 ("drm/dp_mst: clear time slots for ports invalid") |
| Cc: Lyude Paul <lyude@redhat.com> |
| Cc: Wayne Lin <Wayne.Lin@amd.com> |
| Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> |
| Cc: Maxime Ripard <mripard@kernel.org> |
| Cc: Thomas Zimmermann <tzimmermann@suse.de> |
| Cc: dri-devel@lists.freedesktop.org |
| Cc: <stable@vger.kernel.org> # v5.5+ |
| Signed-off-by: Lyude Paul <lyude@redhat.com> |
| Link: https://patchwork.freedesktop.org/patch/msgid/20210616035501.3776-2-Wayne.Lin@amd.com |
| Reviewed-by: Lyude Paul <lyude@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/gpu/drm/drm_dp_mst_topology.c | 36 +++++++++------------------------- |
| 1 file changed, 10 insertions(+), 26 deletions(-) |
| |
| --- a/drivers/gpu/drm/drm_dp_mst_topology.c |
| +++ b/drivers/gpu/drm/drm_dp_mst_topology.c |
| @@ -2499,7 +2499,7 @@ drm_dp_mst_handle_conn_stat(struct drm_d |
| { |
| struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; |
| struct drm_dp_mst_port *port; |
| - int old_ddps, old_input, ret, i; |
| + int old_ddps, ret; |
| u8 new_pdt; |
| bool new_mcs; |
| bool dowork = false, create_connector = false; |
| @@ -2531,7 +2531,6 @@ drm_dp_mst_handle_conn_stat(struct drm_d |
| } |
| |
| old_ddps = port->ddps; |
| - old_input = port->input; |
| port->input = conn_stat->input_port; |
| port->ldps = conn_stat->legacy_device_plug_status; |
| port->ddps = conn_stat->displayport_device_plug_status; |
| @@ -2554,28 +2553,6 @@ drm_dp_mst_handle_conn_stat(struct drm_d |
| dowork = false; |
| } |
| |
| - if (!old_input && old_ddps != port->ddps && !port->ddps) { |
| - for (i = 0; i < mgr->max_payloads; i++) { |
| - struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i]; |
| - struct drm_dp_mst_port *port_validated; |
| - |
| - if (!vcpi) |
| - continue; |
| - |
| - port_validated = |
| - container_of(vcpi, struct drm_dp_mst_port, vcpi); |
| - port_validated = |
| - drm_dp_mst_topology_get_port_validated(mgr, port_validated); |
| - if (!port_validated) { |
| - mutex_lock(&mgr->payload_lock); |
| - vcpi->num_slots = 0; |
| - mutex_unlock(&mgr->payload_lock); |
| - } else { |
| - drm_dp_mst_topology_put_port(port_validated); |
| - } |
| - } |
| - } |
| - |
| if (port->connector) |
| drm_modeset_unlock(&mgr->base.lock); |
| else if (create_connector) |
| @@ -3406,8 +3383,15 @@ int drm_dp_update_payload_part1(struct d |
| port = drm_dp_mst_topology_get_port_validated( |
| mgr, port); |
| if (!port) { |
| - mutex_unlock(&mgr->payload_lock); |
| - return -EINVAL; |
| + if (vcpi->num_slots == payload->num_slots) { |
| + cur_slots += vcpi->num_slots; |
| + payload->start_slot = req_payload.start_slot; |
| + continue; |
| + } else { |
| + drm_dbg_kms("Fail:set payload to invalid sink"); |
| + mutex_unlock(&mgr->payload_lock); |
| + return -EINVAL; |
| + } |
| } |
| put_port = true; |
| } |