| From aa0aad57909eb321746325951d66af88a83bc956 Mon Sep 17 00:00:00 2001 |
| From: Lukas Wunner <lukas@wunner.de> |
| Date: Sun, 11 Feb 2018 10:38:28 +0100 |
| Subject: drm/amdgpu: Fix deadlock on runtime suspend |
| |
| From: Lukas Wunner <lukas@wunner.de> |
| |
| commit aa0aad57909eb321746325951d66af88a83bc956 upstream. |
| |
| amdgpu'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 |
| amdgpu'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. |
| |
| Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)") |
| Cc: stable@vger.kernel.org # v4.2+: 27d4ee03078a: workqueue: Allow retrieval of current task's work struct |
| Cc: stable@vger.kernel.org # v4.2+: 25c058ccaf2e: drm: Allow determining if current task is output poll worker |
| Cc: Alex Deucher <alexander.deucher@amd.com> |
| Tested-by: Mike Lothian <mike@fireburn.co.uk> |
| Reviewed-by: Lyude Paul <lyude@redhat.com> |
| Signed-off-by: Lukas Wunner <lukas@wunner.de> |
| Link: https://patchwork.freedesktop.org/patch/msgid/4c9bf72aacae1eef062bd134cd112e0770a7f121.1518338789.git.lukas@wunner.de |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c | 58 ++++++++++++++++--------- |
| 1 file changed, 38 insertions(+), 20 deletions(-) |
| |
| --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c |
| +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c |
| @@ -739,9 +739,11 @@ amdgpu_connector_lvds_detect(struct drm_ |
| 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 amdgpu_encoder *amdgpu_encoder = to_amdgpu_encoder(encoder); |
| @@ -760,8 +762,12 @@ amdgpu_connector_lvds_detect(struct drm_ |
| /* check acpi lid status ??? */ |
| |
| amdgpu_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; |
| } |
| |
| @@ -871,9 +877,11 @@ amdgpu_connector_vga_detect(struct drm_c |
| 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 = amdgpu_connector_best_single_encoder(connector); |
| if (!encoder) |
| @@ -927,8 +935,10 @@ amdgpu_connector_vga_detect(struct drm_c |
| amdgpu_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; |
| } |
| @@ -991,9 +1001,11 @@ amdgpu_connector_dvi_detect(struct drm_c |
| 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 (!force && amdgpu_connector_check_hpd_status_unchanged(connector)) { |
| ret = connector->status; |
| @@ -1118,8 +1130,10 @@ out: |
| amdgpu_connector_update_scratch_regs(connector, ret); |
| |
| 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; |
| } |
| @@ -1362,9 +1376,11 @@ amdgpu_connector_dp_detect(struct drm_co |
| struct drm_encoder *encoder = amdgpu_connector_best_single_encoder(connector); |
| 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 (!force && amdgpu_connector_check_hpd_status_unchanged(connector)) { |
| ret = connector->status; |
| @@ -1432,8 +1448,10 @@ amdgpu_connector_dp_detect(struct drm_co |
| |
| amdgpu_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; |
| } |