wil6210: ADDBA/DELBA flows

Hello Vladimir Kondratiev,

The patch 3277213feb1b: "wil6210: ADDBA/DELBA flows" from Dec 23, 2014, leads to the following static checker warning:

	drivers/net/wireless/ath/wil6210/rx_reorder.c:205 wil_tid_ampdu_rx_alloc()
	error: scheduling with locks held: 'spin_lock:tid_rx_lock'

drivers/net/wireless/ath/wil6210/rx_reorder.c
202 struct wil_tid_ampdu_rx *wil_tid_ampdu_rx_alloc(struct wil6210_priv *wil,
203 int size, u16 ssn)
204 {

   205          struct wil_tid_ampdu_rx *r = kzalloc(sizeof(*r), GFP_KERNEL);
                                                                 ^^^^^^^^^^
   206  
   207          if (!r)
   208                  return NULL;
   209  
   210          r->reorder_buf =
   211                  kcalloc(size, sizeof(struct sk_buff *), GFP_KERNEL);
                                                                ^^^^^^^^^^^
   212          r->reorder_time =
   213                  kcalloc(size, sizeof(unsigned long), GFP_KERNEL);
                                                             ^^^^^^^^^^^
   214          if (!r->reorder_buf || !r->reorder_time) {
   215                  kfree(r->reorder_buf);
   216                  kfree(r->reorder_time);
   217                  kfree(r);
   218                  return NULL;

219 }
220

[ snip ]

   331          spin_lock_bh(&sta->tid_rx_lock);
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

spin lock held.

332
333 wil_tid_ampdu_rx_free(wil, sta->tid_rx[tid]);

   334          sta->tid_rx[tid] = wil_tid_ampdu_rx_alloc(wil, agg_wsize, ssn);
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

function called with the lock held.

   335  
   336          spin_unlock_bh(&sta->tid_rx_lock);

This looks like it would be pretty easy to re-write so the allocation was done before we take the lock if someone knew exactly what the lock was protecting.

regards,
dan carpenter

Dan, thanks for finding this. Will submit patch shortly

Thanks, Vladimir