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

[Kalle Valo]

Christian Marangi <ansuelsmth at gmail.com> writes:

> On Thu, Feb 09, 2023 at 12:35:20PM +0300, Dan Carpenter wrote:
>
>> 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);
>
> thanks for the report. I send a patch to ath mailing list that should
> fix this bug!

Christian, thanks for the patch. For reference here's the patch:

https://patchwork.kernel.org/project/linux-wireless/patch/20230209222622.1751-1-ansuelsmth@gmail.com/

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