[PATCH 4.9 085/206] mei: move write cb to completion on credentials failures

[Greg Kroah-Hartman]

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

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

From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>

commit e09ee853c92011860a4bd2fbdf6126f60fc16bd3 upstream.

The credentials handling was pushed to the write handlers
but error handling wasn't done properly.
Move write callbacks to completion queue to destroy them
and to notify a blocked writer about the failure

Fixes: 136698e535cd1 (mei: push credentials inside the irq write handler)
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 |   20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1536,7 +1536,7 @@ int mei_cl_irq_write(struct mei_cl *cl,
 
 	rets = first_chunk ? mei_cl_tx_flow_ctrl_creds(cl) : 1;
 	if (rets < 0)
-		return rets;
+		goto err;
 
 	if (rets == 0) {
 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
@@ -1570,11 +1570,8 @@ int mei_cl_irq_write(struct mei_cl *cl,
 			cb->buf.size, cb->buf_idx);
 
 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
-	if (rets) {
-		cl->status = rets;
-		list_move_tail(&cb->list, &cmpl_list->list);
-		return rets;
-	}
+	if (rets)
+		goto err;
 
 	cl->status = 0;
 	cl->writing_state = MEI_WRITING;
@@ -1582,14 +1579,21 @@ int mei_cl_irq_write(struct mei_cl *cl,
 	cb->completed = mei_hdr.msg_complete == 1;
 
 	if (first_chunk) {
-		if (mei_cl_tx_flow_ctrl_creds_reduce(cl))
-			return -EIO;
+		if (mei_cl_tx_flow_ctrl_creds_reduce(cl)) {
+			rets = -EIO;
+			goto err;
+		}
 	}
 
 	if (mei_hdr.msg_complete)
 		list_move_tail(&cb->list, &dev->write_waiting_list.list);
 
 	return 0;
+
+err:
+	cl->status = rets;
+	list_move_tail(&cb->list, &cmpl_list->list);
+	return rets;
 }
 
 /**