[bug report] wifi: ath11k: fix peer addition/deletion error on sta band migration

[Dan Carpenter]

Hello Christian Marangi,

The patch d673cb6fe6c0: "wifi: ath11k: fix peer addition/deletion
error on sta band migration" from Sep 22, 2022, leads to the
following Smatch static checker warning:

	drivers/net/wireless/ath/ath11k/peer.c:396 ath11k_peer_create()
	warn: sleeping in atomic context

drivers/net/wireless/ath/ath11k/peer.c
    370 int ath11k_peer_create(struct ath11k *ar, struct ath11k_vif *arvif,
    371                        struct ieee80211_sta *sta, struct peer_create_params *param)
    372 {
    373         struct ath11k_peer *peer;
    374         struct ath11k_sta *arsta;
    375         int ret, fbret;
    376 
    377         lockdep_assert_held(&ar->conf_mutex);
    378 
    379         if (ar->num_peers > (ar->max_num_peers - 1)) {
    380                 ath11k_warn(ar->ab,
    381                             "failed to create peer due to insufficient peer entry resource in firmware\n");
    382                 return -ENOBUFS;
    383         }
    384 
    385         spin_lock_bh(&ar->ab->base_lock);
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Holding a spin lock.

    386         peer = ath11k_peer_find_by_addr(ar->ab, param->peer_addr);
    387         if (peer) {
    388                 if (peer->vdev_id == param->vdev_id) {
    389                         spin_unlock_bh(&ar->ab->base_lock);
    390                         return -EINVAL;
    391                 }
    392 
    393                 /* Assume sta is transitioning to another band.
    394                  * Remove here the peer from rhash.
    395                  */
--> 396                 mutex_lock(&ar->ab->tbl_mtx_lock);
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
So we can't take a mutex.

    397                 ath11k_peer_rhash_delete(ar->ab, peer);
    398                 mutex_unlock(&ar->ab->tbl_mtx_lock);
    399         }
    400         spin_unlock_bh(&ar->ab->base_lock);
    401 
    402         ret = ath11k_wmi_send_peer_create_cmd(ar, param);

regards,
dan carpenter