| From 15734feff2bdac24aa3266c437cffa42851990e3 Mon Sep 17 00:00:00 2001 |
| From: Lukas Wunner <lukas@wunner.de> |
| Date: Sun, 11 Feb 2018 10:38:28 +0100 |
| Subject: drm/radeon: Fix deadlock on runtime suspend |
| |
| From: Lukas Wunner <lukas@wunner.de> |
| |
| commit 15734feff2bdac24aa3266c437cffa42851990e3 upstream. |
| |
| radeon's ->runtime_suspend hook calls drm_kms_helper_poll_disable(), |
| which waits for the output poll worker to finish if it's running. |
| |
| The output poll worker meanwhile calls pm_runtime_get_sync() in |
| radeon's ->detect hooks, which waits for the ongoing suspend to finish, |
| causing a deadlock. |
| |
| Fix by not acquiring a runtime PM ref if the ->detect hooks are called |
| in the output poll worker's context. This is safe because the poll |
| worker is only enabled while runtime active and we know that |
| ->runtime_suspend waits for it to finish. |
| |
| Stack trace for posterity: |
| |
| INFO: task kworker/0:3:31847 blocked for more than 120 seconds |
| Workqueue: events output_poll_execute [drm_kms_helper] |
| Call Trace: |
| schedule+0x3c/0x90 |
| rpm_resume+0x1e2/0x690 |
| __pm_runtime_resume+0x3f/0x60 |
| radeon_lvds_detect+0x39/0xf0 [radeon] |
| output_poll_execute+0xda/0x1e0 [drm_kms_helper] |
| process_one_work+0x14b/0x440 |
| worker_thread+0x48/0x4a0 |
| |
| INFO: task kworker/2:0:10493 blocked for more than 120 seconds. |
| Workqueue: pm pm_runtime_work |
| Call Trace: |
| schedule+0x3c/0x90 |
| schedule_timeout+0x1b3/0x240 |
| wait_for_common+0xc2/0x180 |
| wait_for_completion+0x1d/0x20 |
| flush_work+0xfc/0x1a0 |
| __cancel_work_timer+0xa5/0x1d0 |
| cancel_delayed_work_sync+0x13/0x20 |
| drm_kms_helper_poll_disable+0x1f/0x30 [drm_kms_helper] |
| radeon_pmops_runtime_suspend+0x3d/0xa0 [radeon] |
| pci_pm_runtime_suspend+0x61/0x1a0 |
| vga_switcheroo_runtime_suspend+0x21/0x70 |
| __rpm_callback+0x32/0x70 |
| rpm_callback+0x24/0x80 |
| rpm_suspend+0x12b/0x640 |
| pm_runtime_work+0x6f/0xb0 |
| process_one_work+0x14b/0x440 |
| worker_thread+0x48/0x4a0 |
| |
| Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94147 |
| Fixes: 10ebc0bc0934 ("drm/radeon: add runtime PM support (v2)") |
| Cc: stable@vger.kernel.org # v3.13+: 27d4ee03078a: workqueue: Allow retrieval of current task's work struct |
| Cc: stable@vger.kernel.org # v3.13+: 25c058ccaf2e: drm: Allow determining if current task is output poll worker |
| Cc: Ismo Toijala <ismo.toijala@gmail.com> |
| Cc: Alex Deucher <alexander.deucher@amd.com> |
| Cc: Dave Airlie <airlied@redhat.com> |
| Reviewed-by: Lyude Paul <lyude@redhat.com> |
| Signed-off-by: Lukas Wunner <lukas@wunner.de> |
| Link: https://patchwork.freedesktop.org/patch/msgid/64ea02c44f91dda19bc563902b97bbc699040392.1518338789.git.lukas@wunner.de |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/gpu/drm/radeon/radeon_connectors.c | 74 +++++++++++++++++++---------- |
| 1 file changed, 49 insertions(+), 25 deletions(-) |
| |
| --- a/drivers/gpu/drm/radeon/radeon_connectors.c |
| +++ b/drivers/gpu/drm/radeon/radeon_connectors.c |
| @@ -900,9 +900,11 @@ radeon_lvds_detect(struct drm_connector |
| enum drm_connector_status ret = connector_status_disconnected; |
| int r; |
| |
| - r = pm_runtime_get_sync(connector->dev->dev); |
| - if (r < 0) |
| - return connector_status_disconnected; |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + r = pm_runtime_get_sync(connector->dev->dev); |
| + if (r < 0) |
| + return connector_status_disconnected; |
| + } |
| |
| if (encoder) { |
| struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder); |
| @@ -925,8 +927,12 @@ radeon_lvds_detect(struct drm_connector |
| /* check acpi lid status ??? */ |
| |
| radeon_connector_update_scratch_regs(connector, ret); |
| - pm_runtime_mark_last_busy(connector->dev->dev); |
| - pm_runtime_put_autosuspend(connector->dev->dev); |
| + |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + pm_runtime_mark_last_busy(connector->dev->dev); |
| + pm_runtime_put_autosuspend(connector->dev->dev); |
| + } |
| + |
| return ret; |
| } |
| |
| @@ -1040,9 +1046,11 @@ radeon_vga_detect(struct drm_connector * |
| enum drm_connector_status ret = connector_status_disconnected; |
| int r; |
| |
| - r = pm_runtime_get_sync(connector->dev->dev); |
| - if (r < 0) |
| - return connector_status_disconnected; |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + r = pm_runtime_get_sync(connector->dev->dev); |
| + if (r < 0) |
| + return connector_status_disconnected; |
| + } |
| |
| encoder = radeon_best_single_encoder(connector); |
| if (!encoder) |
| @@ -1109,8 +1117,10 @@ radeon_vga_detect(struct drm_connector * |
| radeon_connector_update_scratch_regs(connector, ret); |
| |
| out: |
| - pm_runtime_mark_last_busy(connector->dev->dev); |
| - pm_runtime_put_autosuspend(connector->dev->dev); |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + pm_runtime_mark_last_busy(connector->dev->dev); |
| + pm_runtime_put_autosuspend(connector->dev->dev); |
| + } |
| |
| return ret; |
| } |
| @@ -1174,9 +1184,11 @@ radeon_tv_detect(struct drm_connector *c |
| if (!radeon_connector->dac_load_detect) |
| return ret; |
| |
| - r = pm_runtime_get_sync(connector->dev->dev); |
| - if (r < 0) |
| - return connector_status_disconnected; |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + r = pm_runtime_get_sync(connector->dev->dev); |
| + if (r < 0) |
| + return connector_status_disconnected; |
| + } |
| |
| encoder = radeon_best_single_encoder(connector); |
| if (!encoder) |
| @@ -1188,8 +1200,12 @@ radeon_tv_detect(struct drm_connector *c |
| if (ret == connector_status_connected) |
| ret = radeon_connector_analog_encoder_conflict_solve(connector, encoder, ret, false); |
| radeon_connector_update_scratch_regs(connector, ret); |
| - pm_runtime_mark_last_busy(connector->dev->dev); |
| - pm_runtime_put_autosuspend(connector->dev->dev); |
| + |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + pm_runtime_mark_last_busy(connector->dev->dev); |
| + pm_runtime_put_autosuspend(connector->dev->dev); |
| + } |
| + |
| return ret; |
| } |
| |
| @@ -1252,9 +1268,11 @@ radeon_dvi_detect(struct drm_connector * |
| enum drm_connector_status ret = connector_status_disconnected; |
| bool dret = false, broken_edid = false; |
| |
| - r = pm_runtime_get_sync(connector->dev->dev); |
| - if (r < 0) |
| - return connector_status_disconnected; |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + r = pm_runtime_get_sync(connector->dev->dev); |
| + if (r < 0) |
| + return connector_status_disconnected; |
| + } |
| |
| if (radeon_connector->detected_hpd_without_ddc) { |
| force = true; |
| @@ -1437,8 +1455,10 @@ out: |
| } |
| |
| exit: |
| - pm_runtime_mark_last_busy(connector->dev->dev); |
| - pm_runtime_put_autosuspend(connector->dev->dev); |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + pm_runtime_mark_last_busy(connector->dev->dev); |
| + pm_runtime_put_autosuspend(connector->dev->dev); |
| + } |
| |
| return ret; |
| } |
| @@ -1689,9 +1709,11 @@ radeon_dp_detect(struct drm_connector *c |
| if (radeon_dig_connector->is_mst) |
| return connector_status_disconnected; |
| |
| - r = pm_runtime_get_sync(connector->dev->dev); |
| - if (r < 0) |
| - return connector_status_disconnected; |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + r = pm_runtime_get_sync(connector->dev->dev); |
| + if (r < 0) |
| + return connector_status_disconnected; |
| + } |
| |
| if (!force && radeon_check_hpd_status_unchanged(connector)) { |
| ret = connector->status; |
| @@ -1778,8 +1800,10 @@ radeon_dp_detect(struct drm_connector *c |
| } |
| |
| out: |
| - pm_runtime_mark_last_busy(connector->dev->dev); |
| - pm_runtime_put_autosuspend(connector->dev->dev); |
| + if (!drm_kms_helper_is_poll_worker()) { |
| + pm_runtime_mark_last_busy(connector->dev->dev); |
| + pm_runtime_put_autosuspend(connector->dev->dev); |
| + } |
| |
| return ret; |
| } |