4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Lyude Paul <lyude@xxxxxxxxxx>
commit 6833fb1ec120bf078e1a527c573a09d4de286224 upstream.
It's true we can't resume the device from poll workers in
nouveau_connector_detect(). We can however, prevent the autosuspend
timer from elapsing immediately if it hasn't already without risking any
sort of deadlock with the runtime suspend/resume operations. So do that
instead of entirely avoiding grabbing a power reference.
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
Reviewed-by: Karol Herbst <kherbst@xxxxxxxxxx>
Acked-by: Daniel Vetter <daniel@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Cc: Lukas Wunner <lukas@xxxxxxxxx>
Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nouveau_connector.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -253,12 +253,16 @@ nouveau_connector_detect(struct drm_conn
nv_connector->edid = NULL;
}
- /* Outputs are only polled while runtime active, so acquiring a
- * runtime PM ref here is unnecessary (and would deadlock upon
- * runtime suspend because it waits for polling to finish).
+ /* Outputs are only polled while runtime active, so resuming the
+ * device here is unnecessary (and would deadlock upon runtime suspend
+ * because it waits for polling to finish). We do however, want to
+ * prevent the autosuspend timer from elapsing during this operation
+ * if possible.
*/
- if (!drm_kms_helper_is_poll_worker()) {
- ret = pm_runtime_get_sync(connector->dev->dev);
+ if (drm_kms_helper_is_poll_worker()) {
+ pm_runtime_get_noresume(dev->dev);
+ } else {
+ ret = pm_runtime_get_sync(dev->dev);
if (ret < 0 && ret != -EACCES)
return conn_status;
}
@@ -329,10 +333,8 @@ detect_analog:
out:
- if (!drm_kms_helper_is_poll_worker()) {
- pm_runtime_mark_last_busy(connector->dev->dev);
- pm_runtime_put_autosuspend(connector->dev->dev);
- }
+ pm_runtime_mark_last_busy(dev->dev);
+ pm_runtime_put_autosuspend(dev->dev);
return conn_status;
}
