The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 73c57a0aa7f672110d3f28c0ac03ec778a21d9d4 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023112415-commute-pacific-3c87@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: 73c57a0aa7f6 ("drm/amd/display: Adjust the MST resume flow") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 73c57a0aa7f672110d3f28c0ac03ec778a21d9d4 Mon Sep 17 00:00:00 2001 From: Wayne Lin <wayne.lin@xxxxxxx> Date: Tue, 22 Aug 2023 16:03:17 +0800 Subject: [PATCH] drm/amd/display: Adjust the MST resume flow [Why] In drm_dp_mst_topology_mgr_resume() today, it will resume the mst branch to be ready handling mst mode and also consecutively do the mst topology probing. Which will cause the dirver have chance to fire hotplug event before restoring the old state. Then Userspace will react to the hotplug event based on a wrong state. [How] Adjust the mst resume flow as: 1. set dpcd to resume mst branch status 2. restore source old state 3. Do mst resume topology probing For drm_dp_mst_topology_mgr_resume(), it's better to adjust it to pull out topology probing work into a 2nd part procedure of the mst resume. Will have a follow up patch in drm. Reviewed-by: Chao-kai Wang <stylon.wang@xxxxxxx> Cc: Mario Limonciello <mario.limonciello@xxxxxxx> Cc: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Acked-by: Stylon Wang <stylon.wang@xxxxxxx> Signed-off-by: Wayne Lin <wayne.lin@xxxxxxx> Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 0e1ce71350d7..8e98dda1e084 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -2355,14 +2355,62 @@ static int dm_late_init(void *handle) return detect_mst_link_for_all_connectors(adev_to_drm(adev)); } +static void resume_mst_branch_status(struct drm_dp_mst_topology_mgr *mgr) +{ + int ret; + u8 guid[16]; + u64 tmp64; + + mutex_lock(&mgr->lock); + if (!mgr->mst_primary) + goto out_fail; + + if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) { + drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); + goto out_fail; + } + + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, + DP_MST_EN | + DP_UP_REQ_EN | + DP_UPSTREAM_IS_SRC); + if (ret < 0) { + drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n"); + goto out_fail; + } + + /* Some hubs forget their guids after they resume */ + ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16); + if (ret != 16) { + drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); + goto out_fail; + } + + if (memchr_inv(guid, 0, 16) == NULL) { + tmp64 = get_jiffies_64(); + memcpy(&guid[0], &tmp64, sizeof(u64)); + memcpy(&guid[8], &tmp64, sizeof(u64)); + + ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, guid, 16); + + if (ret != 16) { + drm_dbg_kms(mgr->dev, "check mstb guid failed - undocked during suspend?\n"); + goto out_fail; + } + } + + memcpy(mgr->mst_primary->guid, guid, 16); + +out_fail: + mutex_unlock(&mgr->lock); +} + static void s3_handle_mst(struct drm_device *dev, bool suspend) { struct amdgpu_dm_connector *aconnector; struct drm_connector *connector; struct drm_connector_list_iter iter; struct drm_dp_mst_topology_mgr *mgr; - int ret; - bool need_hotplug = false; drm_connector_list_iter_begin(dev, &iter); drm_for_each_connector_iter(connector, &iter) { @@ -2384,18 +2432,15 @@ static void s3_handle_mst(struct drm_device *dev, bool suspend) if (!dp_is_lttpr_present(aconnector->dc_link)) try_to_configure_aux_timeout(aconnector->dc_link->ddc, LINK_AUX_DEFAULT_TIMEOUT_PERIOD); - ret = drm_dp_mst_topology_mgr_resume(mgr, true); - if (ret < 0) { - dm_helpers_dp_mst_stop_top_mgr(aconnector->dc_link->ctx, - aconnector->dc_link); - need_hotplug = true; - } + /* TODO: move resume_mst_branch_status() into drm mst resume again + * once topology probing work is pulled out from mst resume into mst + * resume 2nd step. mst resume 2nd step should be called after old + * state getting restored (i.e. drm_atomic_helper_resume()). + */ + resume_mst_branch_status(mgr); } } drm_connector_list_iter_end(&iter); - - if (need_hotplug) - drm_kms_helper_hotplug_event(dev); } static int amdgpu_dm_smu_write_watermarks_table(struct amdgpu_device *adev) @@ -2789,7 +2834,8 @@ static int dm_resume(void *handle) struct dm_atomic_state *dm_state = to_dm_atomic_state(dm->atomic_obj.state); enum dc_connection_type new_connection_type = dc_connection_none; struct dc_state *dc_state; - int i, r, j; + int i, r, j, ret; + bool need_hotplug = false; if (dm->dc->caps.ips_support) { dc_dmub_srv_exit_low_power_state(dm->dc); @@ -2891,7 +2937,7 @@ static int dm_resume(void *handle) continue; /* - * this is the case when traversing through already created + * this is the case when traversing through already created end sink * MST connectors, should be skipped */ if (aconnector && aconnector->mst_root) @@ -2951,6 +2997,27 @@ static int dm_resume(void *handle) dm->cached_state = NULL; + /* Do mst topology probing after resuming cached state*/ + drm_connector_list_iter_begin(ddev, &iter); + drm_for_each_connector_iter(connector, &iter) { + aconnector = to_amdgpu_dm_connector(connector); + if (aconnector->dc_link->type != dc_connection_mst_branch || + aconnector->mst_root) + continue; + + ret = drm_dp_mst_topology_mgr_resume(&aconnector->mst_mgr, true); + + if (ret < 0) { + dm_helpers_dp_mst_stop_top_mgr(aconnector->dc_link->ctx, + aconnector->dc_link); + need_hotplug = true; + } + } + drm_connector_list_iter_end(&iter); + + if (need_hotplug) + drm_kms_helper_hotplug_event(ddev); + amdgpu_dm_irq_resume_late(adev); amdgpu_dm_smu_write_watermarks_table(adev);
