From: Roman Li roman.li@amd.com

[WHY] Hotplug is not detected in headless (no eDP) mode on dcn35x. With no display dcn35x goes to IPS2 powersaving state where HPD interrupt is not handled.

[HOW] Use idle worker thread for periodic detection of HPD in headless mode.

Reviewed-by: Aurabindo Pillai aurabindo.pillai@amd.com Cc: Mario Limonciello mario.limonciello@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Acked-by: Alex Hung alex.hung@amd.com Signed-off-by: Roman Li roman.li@amd.com --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 3 ++ .../amd/display/amdgpu_dm/amdgpu_dm_crtc.c | 48 +++++++++++++++---- .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 5 +- 3 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h index dfcbc1970fe6..5fd1b6b44577 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h @@ -989,4 +989,7 @@ void *dm_allocate_gpu_mem(struct amdgpu_device *adev, enum dc_gpu_mem_alloc_type type, size_t size, long long *addr); + +bool amdgpu_dm_is_headless(struct amdgpu_device *adev); + #endif /* __AMDGPU_DM_H__ */ diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c index e16eecb146fd..99014339aaa3 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c @@ -162,33 +162,63 @@ static void amdgpu_dm_crtc_set_panel_sr_feature( } }

+bool amdgpu_dm_is_headless(struct amdgpu_device *adev) +{ + struct drm_connector *connector; + struct drm_connector_list_iter iter; + struct drm_device *dev; + bool is_headless = true; + + if (adev == NULL) + return true; + + dev = adev->dm.ddev; + + drm_connector_list_iter_begin(dev, &iter); + drm_for_each_connector_iter(connector, &iter) { + + if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK) + continue; + + if (connector->status == connector_status_connected) { + is_headless = false; + break; + } + } + drm_connector_list_iter_end(&iter); + return is_headless; +} + static void amdgpu_dm_idle_worker(struct work_struct *work) { struct idle_workqueue *idle_work;

idle_work = container_of(work, struct idle_workqueue, work); idle_work->dm->idle_workqueue->running = true; - fsleep(HPD_DETECTION_PERIOD_uS); - mutex_lock(&idle_work->dm->dc_lock); + while (idle_work->enable) { - if (!idle_work->dm->dc->idle_optimizations_allowed) + fsleep(HPD_DETECTION_PERIOD_uS); + mutex_lock(&idle_work->dm->dc_lock); + if (!idle_work->dm->dc->idle_optimizations_allowed) { + mutex_unlock(&idle_work->dm->dc_lock); break; - + } dc_allow_idle_optimizations(idle_work->dm->dc, false);

mutex_unlock(&idle_work->dm->dc_lock); fsleep(HPD_DETECTION_TIME_uS); mutex_lock(&idle_work->dm->dc_lock);

- if (!amdgpu_dm_psr_is_active_allowed(idle_work->dm)) + if (!amdgpu_dm_is_headless(idle_work->dm->adev) && + !amdgpu_dm_psr_is_active_allowed(idle_work->dm)) { + mutex_unlock(&idle_work->dm->dc_lock); break; + }

- dc_allow_idle_optimizations(idle_work->dm->dc, true); + if (idle_work->enable) + dc_allow_idle_optimizations(idle_work->dm->dc, true); mutex_unlock(&idle_work->dm->dc_lock); - fsleep(HPD_DETECTION_PERIOD_uS); - mutex_lock(&idle_work->dm->dc_lock); } - mutex_unlock(&idle_work->dm->dc_lock); idle_work->dm->idle_workqueue->running = false; }

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c index 659dd67be1ba..f5e1f2d1c5f2 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c @@ -1239,8 +1239,11 @@ void dm_helpers_enable_periodic_detection(struct dc_context *ctx, bool enable) { struct amdgpu_device *adev = ctx->driver_context;

- if (adev->dm.idle_workqueue) + if (adev->dm.idle_workqueue) { adev->dm.idle_workqueue->enable = enable; + if (enable && !adev->dm.idle_workqueue->running && amdgpu_dm_is_headless(adev)) + schedule_work(&adev->dm.idle_workqueue->work); + } }

void dm_helpers_dp_mst_update_branch_bandwidth(