[PATCH 4.9 051/116] mei: request async autosuspend at the end of enumeration

From: Greg Kroah-Hartman
Date: Fri Jan 06 2017 - 17:00:10 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>

commit d5f8e166c25750adc147b0adf64a62a91653438a upstream.

pm_runtime_autosuspend can take synchronous or asynchronous
paths, Because we are calling pm_runtime_mark_last_busy just before
this most of the cases it takes the asynchronous way. However,
when the FW or driver resets during already running runtime suspend,
the call will result in calling to the driver's rpm callback and results
in a deadlock on device_lock.
The simplest fix is to replace pm_runtime_autosuspend with
asynchronous pm_request_autosuspend.

Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/misc/mei/client.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -686,7 +686,7 @@ void mei_host_client_init(struct mei_dev

pm_runtime_mark_last_busy(dev->dev);
dev_dbg(dev->dev, "rpm: autosuspend\n");
- pm_runtime_autosuspend(dev->dev);
+ pm_request_autosuspend(dev->dev);
}

/**