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

From: Greg Kroah-Hartman
Date: Tue Jan 10 2017 - 08:47:30 EST


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;
}

/**