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Commit af21319f authored by Michal Kazior's avatar Michal Kazior Committed by Kalle Valo
Browse files

ath10k: fix beacon deadlock 



This should fix a very rare occurrence of the following deadlock:

  [<ffffffffa018265e>] ath10k_wmi_tx_beacons_nowait+0x1e/0x50 [ath10k_core]
  [<ffffffffa01829b6>] ath10k_wmi_op_ep_tx_credits+0x16/0x40 [ath10k_core]
  [<ffffffffa017d685>] ath10k_htc_send+0x285/0x3d0 [ath10k_core]
  [<ffffffffa0184b81>] ath10k_wmi_cmd_send_nowait+0x81/0x110 [ath10k_core]
  [<ffffffffa0184c61>] ath10k_wmi_tx_beacon_nowait.part.33+0x51/0x90 [ath10k_core]
  [<ffffffffa0184cd0>] ath10k_wmi_tx_beacons_iter+0x30/0x40 [ath10k_core]
  [<ffffffff81882246>] __iterate_active_interfaces+0xa6/0x100
  [<ffffffffa0184ca0>] ? ath10k_wmi_tx_beacon_nowait.part.33+0x90/0x90 [ath10k_core]
  [<ffffffff818822ae>] ieee80211_iterate_active_interfaces_atomic+0xe/0x10
  [<ffffffffa0182676>] ath10k_wmi_tx_beacons_nowait+0x36/0x50 [ath10k_core]
  [<ffffffffa01829b6>] ath10k_wmi_op_ep_tx_credits+0x16/0x40 [ath10k_core]
  [<ffffffffa017d140>] ath10k_htc_rx+0x280/0x410 [ath10k_core]
  [<ffffffffa01bcbf0>] ? ath10k_ce_completed_recv_next+0x60/0x80 [ath10k_pci]
  [<ffffffffa01bc6ab>] ath10k_pci_ce_recv_data+0x11b/0x1d0 [ath10k_pci]
  [<ffffffffa01bcf44>] ath10k_ce_per_engine_service+0x64/0xc0 [ath10k_pci]
  [<ffffffffa01bcfc2>] ath10k_ce_per_engine_service_any+0x22/0x50 [ath10k_pci]
  [<ffffffffa01bc4d0>] ath10k_pci_tasklet+0x30/0x90 [ath10k_pci]
  [<ffffffff81055a55>] tasklet_action+0xc5/0x100

To prevent this make sure to release ar->data_lock
while calling to ath10k_wmi_beacon_send_ref_nowait().

Signed-off-by: default avatarMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: default avatarKalle Valo <kvalo@qca.qualcomm.com>
parent 9ad50182

drivers/net/wireless/ath/ath10k/core.h

+7 −1
Original line number Diff line number Diff line
@@ -262,6 +262,12 @@ struct ath10k_sta { 


#define ATH10K_VDEV_SETUP_TIMEOUT_HZ (5*HZ)



enum ath10k_beacon_state {

	ATH10K_BEACON_SCHEDULED = 0,

	ATH10K_BEACON_SENDING,

	ATH10K_BEACON_SENT,

};



struct ath10k_vif {

	struct list_head list;
@@ -272,7 +278,7 @@ struct ath10k_vif { 
	u32 dtim_period;

	struct sk_buff *beacon;

	/* protected by data_lock */

	bool beacon_sent;

	enum ath10k_beacon_state beacon_state;

	void *beacon_buf;

	dma_addr_t beacon_paddr;

drivers/net/wireless/ath/ath10k/mac.c

+5 −1
Original line number Diff line number Diff line
@@ -531,10 +531,14 @@ void ath10k_mac_vif_beacon_free(struct ath10k_vif *arvif) 
		dma_unmap_single(ar->dev, ATH10K_SKB_CB(arvif->beacon)->paddr,

				 arvif->beacon->len, DMA_TO_DEVICE);



	if (WARN_ON(arvif->beacon_state != ATH10K_BEACON_SCHEDULED &&

		    arvif->beacon_state != ATH10K_BEACON_SENT))

		return;



	dev_kfree_skb_any(arvif->beacon);



	arvif->beacon = NULL;

	arvif->beacon_sent = false;

	arvif->beacon_state = ATH10K_BEACON_SCHEDULED;

}



static void ath10k_mac_vif_beacon_cleanup(struct ath10k_vif *arvif)

drivers/net/wireless/ath/ath10k/wmi.c

+46 −22
Original line number Diff line number Diff line
@@ -956,30 +956,45 @@ int ath10k_wmi_cmd_send_nowait(struct ath10k *ar, struct sk_buff *skb, 


static void ath10k_wmi_tx_beacon_nowait(struct ath10k_vif *arvif)

{

	struct sk_buff *bcn;

	struct ath10k *ar = arvif->ar;

	struct ath10k_skb_cb *cb;

	struct sk_buff *bcn;

	int ret;



	lockdep_assert_held(&arvif->ar->data_lock);

	spin_lock_bh(&ar->data_lock);



	if (arvif->beacon == NULL)

		return;

	bcn = arvif->beacon;



	if (arvif->beacon_sent)

		return;

	if (!bcn)

		goto unlock;



	bcn = arvif->beacon;

	cb = ATH10K_SKB_CB(bcn);

	ret = ath10k_wmi_beacon_send_ref_nowait(arvif->ar, arvif->vdev_id,

						bcn->data, bcn->len, cb->paddr,



	switch (arvif->beacon_state) {

	case ATH10K_BEACON_SENDING:

	case ATH10K_BEACON_SENT:

		break;

	case ATH10K_BEACON_SCHEDULED:

		arvif->beacon_state = ATH10K_BEACON_SENDING;

		spin_unlock_bh(&ar->data_lock);



		ret = ath10k_wmi_beacon_send_ref_nowait(arvif->ar,

							arvif->vdev_id,

							bcn->data, bcn->len,

							cb->paddr,

							cb->bcn.dtim_zero,

							cb->bcn.deliver_cab);

	if (ret)

		return;



	/* We need to retain the arvif->beacon reference for DMA unmapping and

	 * freeing the skbuff later. */

	arvif->beacon_sent = true;

		spin_lock_bh(&ar->data_lock);



		if (ret == 0)

			arvif->beacon_state = ATH10K_BEACON_SENT;

		else

			arvif->beacon_state = ATH10K_BEACON_SCHEDULED;

	}



unlock:

	spin_unlock_bh(&ar->data_lock);

}



static void ath10k_wmi_tx_beacons_iter(void *data, u8 *mac,
@@ -992,12 +1007,10 @@ static void ath10k_wmi_tx_beacons_iter(void *data, u8 *mac, 


static void ath10k_wmi_tx_beacons_nowait(struct ath10k *ar)

{

	spin_lock_bh(&ar->data_lock);

	ieee80211_iterate_active_interfaces_atomic(ar->hw,

						   IEEE80211_IFACE_ITER_NORMAL,

						   ath10k_wmi_tx_beacons_iter,

						   NULL);

	spin_unlock_bh(&ar->data_lock);

}



static void ath10k_wmi_op_ep_tx_credits(struct ath10k *ar)
@@ -2459,9 +2472,19 @@ void ath10k_wmi_event_host_swba(struct ath10k *ar, struct sk_buff *skb) 
		spin_lock_bh(&ar->data_lock);



		if (arvif->beacon) {

			if (!arvif->beacon_sent)

				ath10k_warn(ar, "SWBA overrun on vdev %d\n",

			switch (arvif->beacon_state) {

			case ATH10K_BEACON_SENT:

				break;

			case ATH10K_BEACON_SCHEDULED:

				ath10k_warn(ar, "SWBA overrun on vdev %d, skipped old beacon\n",

					    arvif->vdev_id);

				break;

			case ATH10K_BEACON_SENDING:

				ath10k_warn(ar, "SWBA overrun on vdev %d, skipped new beacon\n",

					    arvif->vdev_id);

				dev_kfree_skb(bcn);

				goto skip;

			}



			ath10k_mac_vif_beacon_free(arvif);

		}
@@ -2489,15 +2512,16 @@ void ath10k_wmi_event_host_swba(struct ath10k *ar, struct sk_buff *skb) 
		}



		arvif->beacon = bcn;

		arvif->beacon_sent = false;

		arvif->beacon_state = ATH10K_BEACON_SCHEDULED;



		trace_ath10k_tx_hdr(ar, bcn->data, bcn->len);

		trace_ath10k_tx_payload(ar, bcn->data, bcn->len);



		ath10k_wmi_tx_beacon_nowait(arvif);

skip:

		spin_unlock_bh(&ar->data_lock);

	}



	ath10k_wmi_tx_beacons_nowait(ar);

}



void ath10k_wmi_event_tbttoffset_update(struct ath10k *ar, struct sk_buff *skb)