The patch below does not apply to the 4.4-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From aa0aad57909eb321746325951d66af88a83bc956 Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas@xxxxxxxxx>
Date: Sun, 11 Feb 2018 10:38:28 +0100
Subject: [PATCH] drm/amdgpu: Fix deadlock on runtime suspend
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@xxxxxxxxxxxxxxx # v4.2+: 27d4ee03078a: workqueue: Allow retrieval of current task's work struct
Cc: stable@xxxxxxxxxxxxxxx # v4.2+: 25c058ccaf2e: drm: Allow determining if current task is output poll worker
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Tested-by: Mike Lothian <mike@xxxxxxxxxxxxxx>
Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/4c9bf72aacae1eef062bd134cd112e0770a7f121.1518338789.git.lukas@xxxxxxxxx
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
index df9cbc78e168..21e7ae159dff 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
@@ -737,9 +737,11 @@ amdgpu_connector_lvds_detect(struct drm_connector *connector, bool force)
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);
@@ -758,8 +760,12 @@ amdgpu_connector_lvds_detect(struct drm_connector *connector, bool force)
/* 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;
}
@@ -869,9 +875,11 @@ amdgpu_connector_vga_detect(struct drm_connector *connector, bool force)
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)
@@ -925,8 +933,10 @@ amdgpu_connector_vga_detect(struct drm_connector *connector, bool force)
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;
}
@@ -989,9 +999,11 @@ amdgpu_connector_dvi_detect(struct drm_connector *connector, bool force)
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;
@@ -1116,8 +1128,10 @@ amdgpu_connector_dvi_detect(struct drm_connector *connector, bool force)
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;
}
@@ -1360,9 +1374,11 @@ amdgpu_connector_dp_detect(struct drm_connector *connector, bool force)
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;
@@ -1430,8 +1446,10 @@ amdgpu_connector_dp_detect(struct drm_connector *connector, bool force)
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;
}