ath11k: fix warning caused by lockdep_assert_held

Fix warning caused by lockdep_assert_held when CONFIG_LOCKDEP is enabled.

[  271.940647] WARNING: CPU: 6 PID: 0 at drivers/net/wireless/ath/ath11k/hal.c:818 ath11k_hal_srng_access_begin+0x31/0x40 [ath11k]
[  271.940655] Modules linked in: qrtr_mhi qrtr ns ath11k_pci mhi ath11k qmi_helpers nvme nvme_core
[  271.940675] CPU: 6 PID: 0 Comm: swapper/6 Kdump: loaded Tainted: G        W         5.9.0-rc5-kalle-bringup-wt-ath+ #4
[  271.940682] Hardware name: Dell Inc. Inspiron 7590/08717F, BIOS 1.3.0 07/22/2019
[  271.940698] RIP: 0010:ath11k_hal_srng_access_begin+0x31/0x40 [ath11k]
[  271.940708] Code: 48 89 f3 85 c0 75 11 48 8b 83 a8 00 00 00 8b 00 89 83 b0 00 00 00 5b c3 48 8d 7e 58 be ff ff ff ff e8 53 24 ec fa 85 c0 75 dd <0f> 0b eb d9 90 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 8b 35
[  271.940718] RSP: 0018:ffffbdf0c0230df8 EFLAGS: 00010246
[  271.940727] RAX: 0000000000000000 RBX: ffffa12b34e67680 RCX: ffffa12b57a0d800
[  271.940735] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffa12b34e676d8
[  271.940742] RBP: ffffa12b34e60000 R08: 0000000000000001 R09: 0000000000000001
[  271.940753] R10: 0000000000000001 R11: 0000000000000046 R12: 0000000000000000
[  271.940763] R13: ffffa12b34e60000 R14: ffffa12b34e60000 R15: 0000000000000000
[  271.940774] FS:  0000000000000000(0000) GS:ffffa12b5a400000(0000) knlGS:0000000000000000
[  271.940788] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  271.940798] CR2: 00007f8bef282008 CR3: 00000001f4224004 CR4: 00000000003706e0
[  271.940805] Call Trace:
[  271.940813]  <IRQ>
[  271.940835]  ath11k_dp_tx_completion_handler+0x9e/0x950 [ath11k]
[  271.940847]  ? lock_acquire+0xba/0x3b0
[  271.940876]  ath11k_dp_service_srng+0x5a/0x2e0 [ath11k]
[  271.940893]  ath11k_pci_ext_grp_napi_poll+0x1e/0x80 [ath11k_pci]
[  271.940908]  net_rx_action+0x283/0x4f0
[  271.940931]  __do_softirq+0xcb/0x499
[  271.940950]  asm_call_on_stack+0x12/0x20
[  271.940963]  </IRQ>
[  271.940979]  do_softirq_own_stack+0x4d/0x60
[  271.940991]  irq_exit_rcu+0xb0/0xc0
[  271.941001]  common_interrupt+0xce/0x190
[  271.941014]  asm_common_interrupt+0x1e/0x40
[  271.941026] RIP: 0010:cpuidle_enter_state+0x115/0x500

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1
Signed-off-by: Carl Huang <cjhuang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1601463073-12106-5-git-send-email-kvalo@codeaurora.org

drivers/net/wireless/ath/ath11k/dp_tx.c

@@ -536,6 +536,8 @@ void ath11k_dp_tx_completion_handler(struct ath11k_base *ab, int ring_id)
 	u32 msdu_id;
 	u8 mac_id;
 
+	spin_lock_bh(&status_ring->lock);
+
 	ath11k_hal_srng_access_begin(ab, status_ring);
 
 	while ((ATH11K_TX_COMPL_NEXT(tx_ring->tx_status_head) !=
@@ -555,6 +557,8 @@ void ath11k_dp_tx_completion_handler(struct ath11k_base *ab, int ring_id)
 
 	ath11k_hal_srng_access_end(ab, status_ring);
 
+	spin_unlock_bh(&status_ring->lock);
+
 	while (ATH11K_TX_COMPL_NEXT(tx_ring->tx_status_tail) != tx_ring->tx_status_head) {
 		struct hal_wbm_release_ring *tx_status;
 		u32 desc_id;