wifi: ath11k: fix a possible dead lock caused by ab->base_lock

spin_lock()/spin_unlock() are used in ath11k_reg_chan_list_event() to
acquire/release ab->base_lock. For now this is safe because that
function is only called in soft IRQ context.

But ath11k_reg_chan_list_event() will be called from process
context in an upcoming patch, and this can result in a deadlock if
ab->base_lock is acquired in process context and then soft IRQ occurs
on the same CPU and tries to acquire that lock.

Fix it by using spin_lock_bh() and spin_unlock_bh() instead.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23

Fixes: 69a0fcf8a9f2 ("ath11k: Avoid reg rules update during firmware recovery")
Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20231218085844.2658-4-quic_bqiang@quicinc.com

diff --git a/drivers/net/wireless/ath/ath11k/reg.c b/drivers/net/wireless/ath/ath11k/reg.c
index adcd9063a59c3373fcd55624a19de9b5ad1c5ca6..d4fd3509e608c6bdb1ab0c3fcebfc3a03e6ec404 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/reg.c
+++ b/drivers/net/wireless/ath/ath11k/reg.c
@@ -852,13 +852,13 @@ int ath11k_reg_handle_chan_list(struct ath11k_base *ab,
        /* Avoid default reg rule updates sent during FW recovery if
         * it is already available
         */
-       spin_lock(&ab->base_lock);
+       spin_lock_bh(&ab->base_lock);
        if (test_bit(ATH11K_FLAG_RECOVERY, &ab->dev_flags) &&
            ab->default_regd[pdev_idx]) {
-               spin_unlock(&ab->base_lock);
+               spin_unlock_bh(&ab->base_lock);
                goto retfail;
        }
-       spin_unlock(&ab->base_lock);
+       spin_unlock_bh(&ab->base_lock);
 
        if (pdev_idx >= ab->num_radios) {
                /* Process the event for phy0 only if single_pdev_only
@@ -911,7 +911,7 @@ int ath11k_reg_handle_chan_list(struct ath11k_base *ab,
                ab->reg_info_store[pdev_idx] = *reg_info;
        }
 
-       spin_lock(&ab->base_lock);
+       spin_lock_bh(&ab->base_lock);
        if (ab->default_regd[pdev_idx]) {
                /* The initial rules from FW after WMI Init is to build
                 * the default regd. From then on, any rules updated for
@@ -931,7 +931,7 @@ int ath11k_reg_handle_chan_list(struct ath11k_base *ab,
                ab->default_regd[pdev_idx] = regd;
        }
        ab->dfs_region = reg_info->dfs_region;
-       spin_unlock(&ab->base_lock);
+       spin_unlock_bh(&ab->base_lock);
 
        return 0;