From: Alan Liu Date: Tue, 27 Jun 2023 04:21:51 +0000 (+0800) Subject: drm/amd/display: Fix race condition when turning off an output alone X-Git-Tag: v6.6-rc1~1^2~20^2~107 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=fff7b95a5046be01df5883b3297139cf21bc8763;p=linux-2.6-block.git drm/amd/display: Fix race condition when turning off an output alone [Why] When 2 threads are doing commit_tail parallelly, one thread could commit new streams to dc state but another thread remove it from dc right away. [How] If we don't have new dm state change from commit_check, then we should not call dc_commit_streams() in commit_tail. A new function amdgpu_dm_commit_streams() is introduced to refator dc_commit_stream() adjacent code and fix this issue. Reviewed-by: Harry Wentland Acked-by: Alan Liu Signed-off-by: Alan Liu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- 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 908e013e12df..44ea0da56374 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -7927,7 +7927,6 @@ static inline uint32_t get_mem_type(struct drm_framebuffer *fb) } static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, - struct dc_state *dc_state, struct drm_device *dev, struct amdgpu_display_manager *dm, struct drm_crtc *pcrtc, @@ -8407,52 +8406,17 @@ static void amdgpu_dm_crtc_copy_transient_flags(struct drm_crtc_state *crtc_stat stream_state->mode_changed = drm_atomic_crtc_needs_modeset(crtc_state); } -/** - * amdgpu_dm_atomic_commit_tail() - AMDgpu DM's commit tail implementation. - * @state: The atomic state to commit - * - * This will tell DC to commit the constructed DC state from atomic_check, - * programming the hardware. Any failures here implies a hardware failure, since - * atomic check should have filtered anything non-kosher. - */ -static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) +static void amdgpu_dm_commit_streams(struct drm_atomic_state *state, + struct dc_state *dc_state) { struct drm_device *dev = state->dev; struct amdgpu_device *adev = drm_to_adev(dev); struct amdgpu_display_manager *dm = &adev->dm; - struct dm_atomic_state *dm_state; - struct dc_state *dc_state = NULL, *dc_state_temp = NULL; - u32 i, j; struct drm_crtc *crtc; struct drm_crtc_state *old_crtc_state, *new_crtc_state; - unsigned long flags; - bool wait_for_vblank = true; - struct drm_connector *connector; - struct drm_connector_state *old_con_state, *new_con_state; struct dm_crtc_state *dm_old_crtc_state, *dm_new_crtc_state; - int crtc_disable_count = 0; bool mode_set_reset_required = false; - int r; - - trace_amdgpu_dm_atomic_commit_tail_begin(state); - - r = drm_atomic_helper_wait_for_fences(dev, state, false); - if (unlikely(r)) - DRM_ERROR("Waiting for fences timed out!"); - - drm_atomic_helper_update_legacy_modeset_state(dev, state); - drm_dp_mst_atomic_wait_for_dependencies(state); - - dm_state = dm_atomic_get_new_state(state); - if (dm_state && dm_state->context) { - dc_state = dm_state->context; - } else { - /* No state changes, retain current state. */ - dc_state_temp = dc_create_state(dm->dc); - ASSERT(dc_state_temp); - dc_state = dc_state_temp; - dc_resource_state_copy_construct_current(dm->dc, dc_state); - } + u32 i; for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) { @@ -8551,24 +8515,22 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) } } /* for_each_crtc_in_state() */ - if (dc_state) { - /* if there mode set or reset, disable eDP PSR */ - if (mode_set_reset_required) { - if (dm->vblank_control_workqueue) - flush_workqueue(dm->vblank_control_workqueue); + /* if there mode set or reset, disable eDP PSR */ + if (mode_set_reset_required) { + if (dm->vblank_control_workqueue) + flush_workqueue(dm->vblank_control_workqueue); - amdgpu_dm_psr_disable_all(dm); - } + amdgpu_dm_psr_disable_all(dm); + } - dm_enable_per_frame_crtc_master_sync(dc_state); - mutex_lock(&dm->dc_lock); - WARN_ON(!dc_commit_streams(dm->dc, dc_state->streams, dc_state->stream_count)); + dm_enable_per_frame_crtc_master_sync(dc_state); + mutex_lock(&dm->dc_lock); + WARN_ON(!dc_commit_streams(dm->dc, dc_state->streams, dc_state->stream_count)); - /* Allow idle optimization when vblank count is 0 for display off */ - if (dm->active_vblank_irq_count == 0) - dc_allow_idle_optimizations(dm->dc, true); - mutex_unlock(&dm->dc_lock); - } + /* Allow idle optimization when vblank count is 0 for display off */ + if (dm->active_vblank_irq_count == 0) + dc_allow_idle_optimizations(dm->dc, true); + mutex_unlock(&dm->dc_lock); for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) { struct amdgpu_crtc *acrtc = to_amdgpu_crtc(crtc); @@ -8588,6 +8550,44 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) acrtc->otg_inst = status->primary_otg_inst; } } +} + +/** + * amdgpu_dm_atomic_commit_tail() - AMDgpu DM's commit tail implementation. + * @state: The atomic state to commit + * + * This will tell DC to commit the constructed DC state from atomic_check, + * programming the hardware. Any failures here implies a hardware failure, since + * atomic check should have filtered anything non-kosher. + */ +static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) +{ + struct drm_device *dev = state->dev; + struct amdgpu_device *adev = drm_to_adev(dev); + struct amdgpu_display_manager *dm = &adev->dm; + struct dm_atomic_state *dm_state; + struct dc_state *dc_state = NULL; + u32 i, j; + struct drm_crtc *crtc; + struct drm_crtc_state *old_crtc_state, *new_crtc_state; + unsigned long flags; + bool wait_for_vblank = true; + struct drm_connector *connector; + struct drm_connector_state *old_con_state, *new_con_state; + struct dm_crtc_state *dm_old_crtc_state, *dm_new_crtc_state; + int crtc_disable_count = 0; + + trace_amdgpu_dm_atomic_commit_tail_begin(state); + + drm_atomic_helper_update_legacy_modeset_state(dev, state); + drm_dp_mst_atomic_wait_for_dependencies(state); + + dm_state = dm_atomic_get_new_state(state); + if (dm_state && dm_state->context) { + dc_state = dm_state->context; + amdgpu_dm_commit_streams(state, dc_state); + } + for_each_oldnew_connector_in_state(state, connector, old_con_state, new_con_state, i) { struct dm_connector_state *dm_new_con_state = to_dm_connector_state(new_con_state); struct amdgpu_crtc *acrtc = to_amdgpu_crtc(dm_new_con_state->base.crtc); @@ -8865,8 +8865,7 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) dm_new_crtc_state = to_dm_crtc_state(new_crtc_state); if (dm_new_crtc_state->stream) - amdgpu_dm_commit_planes(state, dc_state, dev, - dm, crtc, wait_for_vblank); + amdgpu_dm_commit_planes(state, dev, dm, crtc, wait_for_vblank); } /* Update audio instances for each connector. */ @@ -8921,9 +8920,6 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) for (i = 0; i < crtc_disable_count; i++) pm_runtime_put_autosuspend(dev->dev); pm_runtime_mark_last_busy(dev->dev); - - if (dc_state_temp) - dc_release_state(dc_state_temp); } static int dm_force_atomic_commit(struct drm_connector *connector)