Re: [PATCH 01/10] wifi: ath12k: convert struct ath12k::wmi_mgmt_tx_work to struct wiphy_work

Baochen Qiang
2024-11-27T02:34:11Z

On 11/27/2024 1:11 AM, Kalle Valo wrote:
> From: Kalle Valo <quic_kvalo@quicinc.com>
>
> To simplify locking for the next patches convert struct
> ath12k::wmi_mgmt_tx_work to use wiphy_work. After this
> ath12k_mgmt_over_wmi_tx_work() is called with wiphy_lock() taken. In
> ath12k_core_suspend() we need to take wiphy_lock() because
> ath12k_mac_wait_tx_complete() requires it.
>
> Also add lockdep_assert_wiphy() to document when wiphy_lock() is held.
>
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
> ---
> drivers/net/wireless/ath/ath12k/core.c | 6 ++++++
> drivers/net/wireless/ath/ath12k/core.h | 2 +-
> drivers/net/wireless/ath/ath12k/mac.c | 20 ++++++++++++++++----
> 3 files changed, 23 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath12k/core.c b/drivers/net/wireless/ath/ath12k/core.c
> index c57322221e1d..263a7c789122 100644
> --- a/drivers/net/wireless/ath/ath12k/core.c
> +++ b/drivers/net/wireless/ath/ath12k/core.c
> @@ -79,11 +79,17 @@ int ath12k_core_suspend(struct ath12k_base *ab)
> ar = ab->pdevs[i].ar;
> if (!ar)
> continue;
> +
> + wiphy_lock(ath12k_ar_to_hw(ar)->wiphy);
> +
> ret = ath12k_mac_wait_tx_complete(ar);
> if (ret) {
> + wiphy_unlock(ath12k_ar_to_hw(ar)->wiphy);
> ath12k_warn(ab, "failed to wait tx complete: %d\n", ret);
> return ret;
> }
> +
> + wiphy_unlock(ath12k_ar_to_hw(ar)->wiphy);
> }
>
> /* PM framework skips suspend_late/resume_early callbacks
> diff --git a/drivers/net/wireless/ath/ath12k/core.h b/drivers/net/wireless/ath/ath12k/core.h
> index c1d5e93b679a..5be977008319 100644
> --- a/drivers/net/wireless/ath/ath12k/core.h
> +++ b/drivers/net/wireless/ath/ath12k/core.h
> @@ -679,7 +679,7 @@ struct ath12k {
>
> struct work_struct regd_update_work;
>
> - struct work_struct wmi_mgmt_tx_work;
> + struct wiphy_work wmi_mgmt_tx_work;
> struct sk_buff_head wmi_mgmt_tx_queue;
>
> struct ath12k_wow wow;
> diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
> index 60702bf07141..a6fe998c177e 100644
> --- a/drivers/net/wireless/ath/ath12k/mac.c
> +++ b/drivers/net/wireless/ath/ath12k/mac.c
> @@ -6726,6 +6726,8 @@ static void ath12k_mgmt_over_wmi_tx_drop(struct ath12k *ar, struct sk_buff *skb)
> {
> int num_mgmt;
>
> + lockdep_assert_wiphy(ath12k_ar_to_hw(ar)->wiphy);
why would we need wiphy lock protect here? I don;t see anything in this function need it.

> +
> ieee80211_free_txskb(ath12k_ar_to_hw(ar), skb);
>
> num_mgmt = atomic_dec_if_positive(&ar->num_pending_mgmt_tx);
> @@ -6787,6 +6789,8 @@ static int ath12k_mac_mgmt_tx_wmi(struct ath12k *ar, struct ath12k_link_vif *arv
> int buf_id;
> int ret;
>
> + lockdep_assert_wiphy(ath12k_ar_to_hw(ar)->wiphy);
and here the same question as above. I know this function is only called from
ath12k_mgmt_over_wmi_tx_work() which is under wiphy lock protection. But the function
itself doesn't need to assert it if the function does not need its protection.

> +
> ATH12K_SKB_CB(skb)->ar = ar;
> spin_lock_bh(&ar->txmgmt_idr_lock);
> buf_id = idr_alloc(&ar->txmgmt_idr, skb, 0,
> @@ -6841,7 +6845,7 @@ static void ath12k_mgmt_over_wmi_tx_purge(struct ath12k *ar)
> ath12k_mgmt_over_wmi_tx_drop(ar, skb);
> }
>
> -static void ath12k_mgmt_over_wmi_tx_work(struct work_struct *work)
> +static void ath12k_mgmt_over_wmi_tx_work(struct wiphy *wiphy, struct wiphy_work *work)
> {
> struct ath12k *ar = container_of(work, struct ath12k, wmi_mgmt_tx_work);
> struct ath12k_skb_cb *skb_cb;
> @@ -6850,6 +6854,8 @@ static void ath12k_mgmt_over_wmi_tx_work(struct work_struct *work)
> struct sk_buff *skb;
> int ret;
>
> + lockdep_assert_wiphy(wiphy);
we are definitely under wiphy lock protection since this is a wiphy_work item, hence no
need to assert it explicitly. see also

ieee80211_sta_monitor_work()
ieee80211_beacon_connection_loss_work()
ieee80211_csa_connection_drop_work()
ieee80211_teardown_ttlm_work()

> +
> while ((skb = skb_dequeue(&ar->wmi_mgmt_tx_queue)) != NULL) {
> skb_cb = ATH12K_SKB_CB(skb);
> if (!skb_cb->vif) {
> @@ -6904,7 +6910,7 @@ static int ath12k_mac_mgmt_tx(struct ath12k *ar, struct sk_buff *skb,
>
> skb_queue_tail(q, skb);
> atomic_inc(&ar->num_pending_mgmt_tx);
> - ieee80211_queue_work(ath12k_ar_to_hw(ar), &ar->wmi_mgmt_tx_work);
> + wiphy_work_queue(ath12k_ar_to_hw(ar)->wiphy, &ar->wmi_mgmt_tx_work);
>
> return 0;
> }
> @@ -6981,10 +6987,12 @@ static void ath12k_mac_op_tx(struct ieee80211_hw *hw,
>
> void ath12k_mac_drain_tx(struct ath12k *ar)
> {
> + lockdep_assert_wiphy(ath12k_ar_to_hw(ar)->wiphy);
> +
> /* make sure rcu-protected mac80211 tx path itself is drained */
> synchronize_net();
>
> - cancel_work_sync(&ar->wmi_mgmt_tx_work);
> + wiphy_work_cancel(ath12k_ar_to_hw(ar)->wiphy, &ar->wmi_mgmt_tx_work);
> ath12k_mgmt_over_wmi_tx_purge(ar);
> }
>
> @@ -7101,6 +7109,8 @@ static void ath12k_drain_tx(struct ath12k_hw *ah)
> struct ath12k *ar;
> int i;
>
> + lockdep_assert_wiphy(ah->hw->wiphy);
> +
> for_each_ar(ah, ar, i)
> ath12k_mac_drain_tx(ar);
> }
> @@ -9134,6 +9144,8 @@ static int ath12k_mac_flush(struct ath12k *ar)
>
> int ath12k_mac_wait_tx_complete(struct ath12k *ar)
> {
> + lockdep_assert_wiphy(ath12k_ar_to_hw(ar)->wiphy);
> +
> ath12k_mac_drain_tx(ar);
> return ath12k_mac_flush(ar);
> }
> @@ -10604,7 +10616,7 @@ static void ath12k_mac_setup(struct ath12k *ar)
> INIT_DELAYED_WORK(&ar->scan.timeout, ath12k_scan_timeout_work);
> INIT_WORK(&ar->regd_update_work, ath12k_regd_update_work);
>
> - INIT_WORK(&ar->wmi_mgmt_tx_work, ath12k_mgmt_over_wmi_tx_work);
> + wiphy_work_init(&ar->wmi_mgmt_tx_work, ath12k_mgmt_over_wmi_tx_work);
> skb_queue_head_init(&ar->wmi_mgmt_tx_queue);
> }
>