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* [PATCH AUTOSEL 5.11 01/67] ath10k: prevent deinitializing NAPI twice
@ 2021-02-24 12:49 Sasha Levin
  2021-02-24 12:49 ` [PATCH AUTOSEL 5.11 14/67] ath10k: fix wmi mgmt tx queue full due to race condition Sasha Levin
  0 siblings, 1 reply; 2+ messages in thread
From: Sasha Levin @ 2021-02-24 12:49 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Sasha Levin, netdev, linux-wireless, ath10k, Wen Gong, Kalle Valo

From: Wen Gong <wgong@codeaurora.org>

[ Upstream commit e2f8b74e58cb1560c1399ba94a470b770e858259 ]

It happened "Kernel panic - not syncing: hung_task: blocked tasks" when
test simulate crash and ifconfig down/rmmod meanwhile.

Test steps:

1.Test commands, either can reproduce the hang for PCIe, SDIO and SNOC.
echo soft > /sys/kernel/debug/ieee80211/phy0/ath10k/simulate_fw_crash;sleep 0.05;ifconfig wlan0 down
echo soft > /sys/kernel/debug/ieee80211/phy0/ath10k/simulate_fw_crash;rmmod ath10k_sdio
echo hw-restart > /sys/kernel/debug/ieee80211/phy0/ath10k/simulate_fw_crash;rmmod ath10k_pci

2. dmesg:
[ 5622.548630] ath10k_sdio mmc1:0001:1: simulating soft firmware crash
[ 5622.655995] ieee80211 phy0: Hardware restart was requested
[ 5776.355164] INFO: task shill:1572 blocked for more than 122 seconds.
[ 5776.355687] INFO: task kworker/1:2:24437 blocked for more than 122 seconds.
[ 5776.359812] Kernel panic - not syncing: hung_task: blocked tasks
[ 5776.359836] CPU: 1 PID: 55 Comm: khungtaskd Tainted: G        W         4.19.86 #137
[ 5776.359846] Hardware name: MediaTek krane sku176 board (DT)
[ 5776.359855] Call trace:
[ 5776.359868]  dump_backtrace+0x0/0x170
[ 5776.359881]  show_stack+0x20/0x2c
[ 5776.359896]  dump_stack+0xd4/0x10c
[ 5776.359916]  panic+0x12c/0x29c
[ 5776.359937]  hung_task_panic+0x0/0x50
[ 5776.359953]  kthread+0x120/0x130
[ 5776.359965]  ret_from_fork+0x10/0x18
[ 5776.359986] SMP: stopping secondary CPUs
[ 5776.360012] Kernel Offset: 0x141ea00000 from 0xffffff8008000000
[ 5776.360026] CPU features: 0x0,2188200c
[ 5776.360035] Memory Limit: none

command "ifconfig wlan0 down" or "rmmod ath10k_sdio" will be blocked
callstack of ifconfig:
[<0>] __switch_to+0x120/0x13c
[<0>] msleep+0x28/0x38
[<0>] ath10k_sdio_hif_stop+0x24c/0x294 [ath10k_sdio]
[<0>] ath10k_core_stop+0x50/0x78 [ath10k_core]
[<0>] ath10k_halt+0x120/0x178 [ath10k_core]
[<0>] ath10k_stop+0x4c/0x8c [ath10k_core]
[<0>] drv_stop+0xe0/0x1e4 [mac80211]
[<0>] ieee80211_stop_device+0x48/0x54 [mac80211]
[<0>] ieee80211_do_stop+0x678/0x6f8 [mac80211]
[<0>] ieee80211_stop+0x20/0x30 [mac80211]
[<0>] __dev_close_many+0xb8/0x11c
[<0>] __dev_change_flags+0xe0/0x1d0
[<0>] dev_change_flags+0x30/0x6c
[<0>] devinet_ioctl+0x370/0x564
[<0>] inet_ioctl+0xdc/0x304
[<0>] sock_do_ioctl+0x50/0x288
[<0>] compat_sock_ioctl+0x1b4/0x1aac
[<0>] __se_compat_sys_ioctl+0x100/0x26fc
[<0>] __arm64_compat_sys_ioctl+0x20/0x2c
[<0>] el0_svc_common+0xa4/0x154
[<0>] el0_svc_compat_handler+0x2c/0x38
[<0>] el0_svc_compat+0x8/0x18
[<0>] 0xffffffffffffffff

callstack of rmmod:
[<0>] __switch_to+0x120/0x13c
[<0>] msleep+0x28/0x38
[<0>] ath10k_sdio_hif_stop+0x294/0x31c [ath10k_sdio]
[<0>] ath10k_core_stop+0x50/0x78 [ath10k_core]
[<0>] ath10k_halt+0x120/0x178 [ath10k_core]
[<0>] ath10k_stop+0x4c/0x8c [ath10k_core]
[<0>] drv_stop+0xe0/0x1e4 [mac80211]
[<0>] ieee80211_stop_device+0x48/0x54 [mac80211]
[<0>] ieee80211_do_stop+0x678/0x6f8 [mac80211]
[<0>] ieee80211_stop+0x20/0x30 [mac80211]
[<0>] __dev_close_many+0xb8/0x11c
[<0>] dev_close_many+0x70/0x100
[<0>] dev_close+0x4c/0x80
[<0>] cfg80211_shutdown_all_interfaces+0x50/0xcc [cfg80211]
[<0>] ieee80211_remove_interfaces+0x58/0x1a0 [mac80211]
[<0>] ieee80211_unregister_hw+0x40/0x100 [mac80211]
[<0>] ath10k_mac_unregister+0x1c/0x44 [ath10k_core]
[<0>] ath10k_core_unregister+0x38/0x7c [ath10k_core]
[<0>] ath10k_sdio_remove+0x8c/0xd0 [ath10k_sdio]
[<0>] sdio_bus_remove+0x48/0x108
[<0>] device_release_driver_internal+0x138/0x1ec
[<0>] driver_detach+0x6c/0xa8
[<0>] bus_remove_driver+0x78/0xa8
[<0>] driver_unregister+0x30/0x50
[<0>] sdio_unregister_driver+0x28/0x34
[<0>] cleanup_module+0x14/0x6bc [ath10k_sdio]
[<0>] __arm64_sys_delete_module+0x1e0/0x22c
[<0>] el0_svc_common+0xa4/0x154
[<0>] el0_svc_compat_handler+0x2c/0x38
[<0>] el0_svc_compat+0x8/0x18
[<0>] 0xffffffffffffffff

SNOC:
[  647.156863] Call trace:
[  647.162166] [<ffffff80080855a4>] __switch_to+0x120/0x13c
[  647.164512] [<ffffff800899d8b8>] __schedule+0x5ec/0x798
[  647.170062] [<ffffff800899dad8>] schedule+0x74/0x94
[  647.175050] [<ffffff80089a0848>] schedule_timeout+0x314/0x42c
[  647.179874] [<ffffff80089a0a14>] schedule_timeout_uninterruptible+0x34/0x40
[  647.185780] [<ffffff80082a494>] msleep+0x28/0x38
[  647.192546] [<ffffff800117ec4c>] ath10k_snoc_hif_stop+0x4c/0x1e0 [ath10k_snoc]
[  647.197439] [<ffffff80010dfbd8>] ath10k_core_stop+0x50/0x7c [ath10k_core]
[  647.204652] [<ffffff80010c8f48>] ath10k_halt+0x114/0x16c [ath10k_core]
[  647.211420] [<ffffff80010cad68>] ath10k_stop+0x4c/0x88 [ath10k_core]
[  647.217865] [<ffffff8000fdbf54>] drv_stop+0x110/0x244 [mac80211]
[  647.224367] [<ffffff80010147ac>] ieee80211_stop_device+0x48/0x54 [mac80211]
[  647.230359] [<ffffff8000ff3eec>] ieee80211_do_stop+0x6a4/0x73c [mac80211]
[  647.237033] [<ffffff8000ff4500>] ieee80211_stop+0x20/0x30 [mac80211]
[  647.243942] [<ffffff80087e39b8>] __dev_close_many+0xa0/0xfc
[  647.250435] [<ffffff80087e3888>] dev_close_many+0x70/0x100
[  647.255651] [<ffffff80087e3a60>] dev_close+0x4c/0x80
[  647.261244] [<ffffff8000f1ba54>] cfg80211_shutdown_all_interfaces+0x44/0xcc [cfg80211]
[  647.266383] [<ffffff8000ff3fdc>] ieee80211_remove_interfaces+0x58/0x1b4 [mac80211]
[  647.274128] [<ffffff8000fda540>] ieee80211_unregister_hw+0x50/0x120 [mac80211]
[  647.281659] [<ffffff80010ca314>] ath10k_mac_unregister+0x1c/0x44 [ath10k_core]
[  647.288839] [<ffffff80010dfc94>] ath10k_core_unregister+0x48/0x90 [ath10k_core]
[  647.296027] [<ffffff800117e598>] ath10k_snoc_remove+0x5c/0x150 [ath10k_snoc]
[  647.303229] [<ffffff80085625fc>] platform_drv_remove+0x28/0x50
[  647.310517] [<ffffff80085601a4>] device_release_driver_internal+0x114/0x1b8
[  647.316257] [<ffffff80085602e4>] driver_detach+0x6c/0xa8
[  647.323021] [<ffffff800855e5b8>] bus_remove_driver+0x78/0xa8
[  647.328571] [<ffffff800856107c>] driver_unregister+0x30/0x50
[  647.334213] [<ffffff8008562674>] platform_driver_unregister+0x1c/0x28
[  647.339876] [<ffffff800117fefc>] cleanup_module+0x1c/0x120 [ath10k_snoc]
[  647.346196] [<ffffff8008143ab8>] SyS_delete_module+0x1dc/0x22c

PCIe:
[  615.392770] rmmod           D    0  3523   3458 0x00000080
[  615.392777] Call Trace:
[  615.392784]  __schedule+0x617/0x7d3
[  615.392791]  ? __mod_timer+0x263/0x35c
[  615.392797]  schedule+0x62/0x72
[  615.392803]  schedule_timeout+0x8d/0xf3
[  615.392809]  ? run_local_timers+0x6b/0x6b
[  615.392814]  msleep+0x1b/0x22
[  615.392824]  ath10k_pci_hif_stop+0x68/0xd6 [ath10k_pci]
[  615.392844]  ath10k_core_stop+0x44/0x67 [ath10k_core]
[  615.392859]  ath10k_halt+0x102/0x153 [ath10k_core]
[  615.392873]  ath10k_stop+0x38/0x75 [ath10k_core]
[  615.392893]  drv_stop+0x9a/0x13c [mac80211]
[  615.392915]  ieee80211_do_stop+0x772/0x7cd [mac80211]
[  615.392937]  ieee80211_stop+0x1a/0x1e [mac80211]
[  615.392945]  __dev_close_many+0x9e/0xf0
[  615.392952]  dev_close_many+0x62/0xe8
[  615.392958]  dev_close+0x54/0x7d
[  615.392975]  cfg80211_shutdown_all_interfaces+0x6e/0xa5 [cfg80211]
[  615.393021]  ieee80211_remove_interfaces+0x52/0x1aa [mac80211]
[  615.393049]  ieee80211_unregister_hw+0x54/0x136 [mac80211]
[  615.393068]  ath10k_mac_unregister+0x19/0x4a [ath10k_core]
[  615.393091]  ath10k_core_unregister+0x39/0x7e [ath10k_core]
[  615.393104]  ath10k_pci_remove+0x3d/0x7f [ath10k_pci]
[  615.393117]  pci_device_remove+0x41/0xa6
[  615.393129]  device_release_driver_internal+0x123/0x1ec
[  615.393140]  driver_detach+0x60/0x90
[  615.393152]  bus_remove_driver+0x72/0x9f
[  615.393164]  pci_unregister_driver+0x1e/0x87
[  615.393177]  SyS_delete_module+0x1d7/0x277
[  615.393188]  do_syscall_64+0x6b/0xf7
[  615.393199]  entry_SYSCALL_64_after_hwframe+0x41/0xa6

The test command run simulate_fw_crash firstly and it call into
ath10k_sdio_hif_stop from ath10k_core_restart, then napi_disable
is called and bit NAPI_STATE_SCHED is set. After that, function
ath10k_sdio_hif_stop is called again from ath10k_stop by command
"ifconfig wlan0 down" or "rmmod ath10k_sdio", then command blocked.

It is blocked by napi_synchronize, napi_disable will set bit with
NAPI_STATE_SCHED, and then napi_synchronize will enter dead loop
becuase bit NAPI_STATE_SCHED is set by napi_disable.

function of napi_synchronize
static inline void napi_synchronize(const struct napi_struct *n)
{
	if (IS_ENABLED(CONFIG_SMP))
		while (test_bit(NAPI_STATE_SCHED, &n->state))
			msleep(1);
	else
		barrier();
}

function of napi_disable
void napi_disable(struct napi_struct *n)
{
	might_sleep();
	set_bit(NAPI_STATE_DISABLE, &n->state);

	while (test_and_set_bit(NAPI_STATE_SCHED, &n->state))
		msleep(1);
	while (test_and_set_bit(NAPI_STATE_NPSVC, &n->state))
		msleep(1);

	hrtimer_cancel(&n->timer);

	clear_bit(NAPI_STATE_DISABLE, &n->state);
}

Add flag for it avoid the hang and crash.

Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00049
Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00110-QCARMSWP-1
Tested-on: WCN3990 hw1.0 SNOC hw1.0 WLAN.HL.3.1-01307.1-QCAHLSWMTPL-2

Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1598617348-2325-1-git-send-email-wgong@codeaurora.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/ath/ath10k/ahb.c  |  5 ++---
 drivers/net/wireless/ath/ath10k/core.c | 25 +++++++++++++++++++++++++
 drivers/net/wireless/ath/ath10k/core.h |  5 +++++
 drivers/net/wireless/ath/ath10k/pci.c  |  7 ++++---
 drivers/net/wireless/ath/ath10k/sdio.c |  5 ++---
 drivers/net/wireless/ath/ath10k/snoc.c |  6 +++---
 6 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/ahb.c b/drivers/net/wireless/ath/ath10k/ahb.c
index 05a61975c83f4..869524852fbaa 100644
--- a/drivers/net/wireless/ath/ath10k/ahb.c
+++ b/drivers/net/wireless/ath/ath10k/ahb.c
@@ -626,7 +626,7 @@ static int ath10k_ahb_hif_start(struct ath10k *ar)
 {
 	ath10k_dbg(ar, ATH10K_DBG_BOOT, "boot ahb hif start\n");
 
-	napi_enable(&ar->napi);
+	ath10k_core_napi_enable(ar);
 	ath10k_ce_enable_interrupts(ar);
 	ath10k_pci_enable_legacy_irq(ar);
 
@@ -644,8 +644,7 @@ static void ath10k_ahb_hif_stop(struct ath10k *ar)
 	ath10k_ahb_irq_disable(ar);
 	synchronize_irq(ar_ahb->irq);
 
-	napi_synchronize(&ar->napi);
-	napi_disable(&ar->napi);
+	ath10k_core_napi_sync_disable(ar);
 
 	ath10k_pci_flush(ar);
 }
diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index eeb6ff6aa2e1e..a419ec7130f97 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -2305,6 +2305,31 @@ void ath10k_core_start_recovery(struct ath10k *ar)
 }
 EXPORT_SYMBOL(ath10k_core_start_recovery);
 
+void ath10k_core_napi_enable(struct ath10k *ar)
+{
+	lockdep_assert_held(&ar->conf_mutex);
+
+	if (test_bit(ATH10K_FLAG_NAPI_ENABLED, &ar->dev_flags))
+		return;
+
+	napi_enable(&ar->napi);
+	set_bit(ATH10K_FLAG_NAPI_ENABLED, &ar->dev_flags);
+}
+EXPORT_SYMBOL(ath10k_core_napi_enable);
+
+void ath10k_core_napi_sync_disable(struct ath10k *ar)
+{
+	lockdep_assert_held(&ar->conf_mutex);
+
+	if (!test_bit(ATH10K_FLAG_NAPI_ENABLED, &ar->dev_flags))
+		return;
+
+	napi_synchronize(&ar->napi);
+	napi_disable(&ar->napi);
+	clear_bit(ATH10K_FLAG_NAPI_ENABLED, &ar->dev_flags);
+}
+EXPORT_SYMBOL(ath10k_core_napi_sync_disable);
+
 static void ath10k_core_restart(struct work_struct *work)
 {
 	struct ath10k *ar = container_of(work, struct ath10k, restart_work);
diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
index 51f7e960e2977..f4be6bfb25392 100644
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -868,6 +868,9 @@ enum ath10k_dev_flags {
 
 	/* Indicates that ath10k device is during recovery process and not complete */
 	ATH10K_FLAG_RESTARTING,
+
+	/* protected by conf_mutex */
+	ATH10K_FLAG_NAPI_ENABLED,
 };
 
 enum ath10k_cal_mode {
@@ -1308,6 +1311,8 @@ static inline bool ath10k_peer_stats_enabled(struct ath10k *ar)
 
 extern unsigned long ath10k_coredump_mask;
 
+void ath10k_core_napi_sync_disable(struct ath10k *ar);
+void ath10k_core_napi_enable(struct ath10k *ar);
 struct ath10k *ath10k_core_create(size_t priv_size, struct device *dev,
 				  enum ath10k_bus bus,
 				  enum ath10k_hw_rev hw_rev,
diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c
index 2328df09875ce..e7fde635e0eef 100644
--- a/drivers/net/wireless/ath/ath10k/pci.c
+++ b/drivers/net/wireless/ath/ath10k/pci.c
@@ -1958,7 +1958,7 @@ static int ath10k_pci_hif_start(struct ath10k *ar)
 
 	ath10k_dbg(ar, ATH10K_DBG_BOOT, "boot hif start\n");
 
-	napi_enable(&ar->napi);
+	ath10k_core_napi_enable(ar);
 
 	ath10k_pci_irq_enable(ar);
 	ath10k_pci_rx_post(ar);
@@ -2075,8 +2075,9 @@ static void ath10k_pci_hif_stop(struct ath10k *ar)
 
 	ath10k_pci_irq_disable(ar);
 	ath10k_pci_irq_sync(ar);
-	napi_synchronize(&ar->napi);
-	napi_disable(&ar->napi);
+
+	ath10k_core_napi_sync_disable(ar);
+
 	cancel_work_sync(&ar_pci->dump_work);
 
 	/* Most likely the device has HTT Rx ring configured. The only way to
diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c
index c415090d1f37c..b746052737e0b 100644
--- a/drivers/net/wireless/ath/ath10k/sdio.c
+++ b/drivers/net/wireless/ath/ath10k/sdio.c
@@ -1859,7 +1859,7 @@ static int ath10k_sdio_hif_start(struct ath10k *ar)
 	struct ath10k_sdio *ar_sdio = ath10k_sdio_priv(ar);
 	int ret;
 
-	napi_enable(&ar->napi);
+	ath10k_core_napi_enable(ar);
 
 	/* Sleep 20 ms before HIF interrupts are disabled.
 	 * This will give target plenty of time to process the BMI done
@@ -1992,8 +1992,7 @@ static void ath10k_sdio_hif_stop(struct ath10k *ar)
 
 	spin_unlock_bh(&ar_sdio->wr_async_lock);
 
-	napi_synchronize(&ar->napi);
-	napi_disable(&ar->napi);
+	ath10k_core_napi_sync_disable(ar);
 }
 
 #ifdef CONFIG_PM
diff --git a/drivers/net/wireless/ath/ath10k/snoc.c b/drivers/net/wireless/ath/ath10k/snoc.c
index bf9a8cb713dc0..2c2df0b8b3fd9 100644
--- a/drivers/net/wireless/ath/ath10k/snoc.c
+++ b/drivers/net/wireless/ath/ath10k/snoc.c
@@ -915,8 +915,7 @@ static void ath10k_snoc_hif_stop(struct ath10k *ar)
 	if (!test_bit(ATH10K_FLAG_CRASH_FLUSH, &ar->dev_flags))
 		ath10k_snoc_irq_disable(ar);
 
-	napi_synchronize(&ar->napi);
-	napi_disable(&ar->napi);
+	ath10k_core_napi_sync_disable(ar);
 	ath10k_snoc_buffer_cleanup(ar);
 	ath10k_dbg(ar, ATH10K_DBG_BOOT, "boot hif stop\n");
 }
@@ -926,7 +925,8 @@ static int ath10k_snoc_hif_start(struct ath10k *ar)
 	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
 
 	bitmap_clear(ar_snoc->pending_ce_irqs, 0, CE_COUNT_MAX);
-	napi_enable(&ar->napi);
+
+	ath10k_core_napi_enable(ar);
 	ath10k_snoc_irq_enable(ar);
 	ath10k_snoc_rx_post(ar);
 
-- 
2.27.0


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^ permalink raw reply	[flat|nested] 2+ messages in thread

* [PATCH AUTOSEL 5.11 14/67] ath10k: fix wmi mgmt tx queue full due to race condition
  2021-02-24 12:49 [PATCH AUTOSEL 5.11 01/67] ath10k: prevent deinitializing NAPI twice Sasha Levin
@ 2021-02-24 12:49 ` Sasha Levin
  0 siblings, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2021-02-24 12:49 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Sasha Levin, Miaoqing Pan, netdev, Brian Norris, linux-wireless,
	ath10k, Kalle Valo

From: Miaoqing Pan <miaoqing@codeaurora.org>

[ Upstream commit b55379e343a3472c35f4a1245906db5158cab453 ]

Failed to transmit wmi management frames:

[84977.840894] ath10k_snoc a000000.wifi: wmi mgmt tx queue is full
[84977.840913] ath10k_snoc a000000.wifi: failed to transmit packet, dropping: -28
[84977.840924] ath10k_snoc a000000.wifi: failed to submit frame: -28
[84977.840932] ath10k_snoc a000000.wifi: failed to transmit frame: -28

This issue is caused by race condition between skb_dequeue and
__skb_queue_tail. The queue of ‘wmi_mgmt_tx_queue’ is protected by a
different lock: ar->data_lock vs list->lock, the result is no protection.
So when ath10k_mgmt_over_wmi_tx_work() and ath10k_mac_tx_wmi_mgmt()
running concurrently on different CPUs, there appear to be a rare corner
cases when the queue length is 1,

  CPUx (skb_deuque)			CPUy (__skb_queue_tail)
					next=list
					prev=list
  struct sk_buff *skb = skb_peek(list);	WRITE_ONCE(newsk->next, next);
  WRITE_ONCE(list->qlen, list->qlen - 1);WRITE_ONCE(newsk->prev, prev);
  next       = skb->next;		WRITE_ONCE(next->prev, newsk);
  prev       = skb->prev;		WRITE_ONCE(prev->next, newsk);
  skb->next  = skb->prev = NULL;	list->qlen++;
  WRITE_ONCE(next->prev, prev);
  WRITE_ONCE(prev->next, next);

If the instruction ‘next = skb->next’ is executed before
‘WRITE_ONCE(prev->next, newsk)’, newsk will be lost, as CPUx get the
old ‘next’ pointer, but the length is still added by one. The final
result is the length of the queue will reach the maximum value but
the queue is empty.

So remove ar->data_lock, and use 'skb_queue_tail' instead of
'__skb_queue_tail' to prevent the potential race condition. Also switch
to use skb_queue_len_lockless, in case we queue a few SKBs simultaneously.

Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.3.1.c2-00033-QCAHLSWMTPLZ-1

Signed-off-by: Miaoqing Pan <miaoqing@codeaurora.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1608618887-8857-1-git-send-email-miaoqing@codeaurora.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/ath/ath10k/mac.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 7d98250380ec5..91b1006ef2a27 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -3763,23 +3763,16 @@ bool ath10k_mac_tx_frm_has_freq(struct ath10k *ar)
 static int ath10k_mac_tx_wmi_mgmt(struct ath10k *ar, struct sk_buff *skb)
 {
 	struct sk_buff_head *q = &ar->wmi_mgmt_tx_queue;
-	int ret = 0;
-
-	spin_lock_bh(&ar->data_lock);
 
-	if (skb_queue_len(q) == ATH10K_MAX_NUM_MGMT_PENDING) {
+	if (skb_queue_len_lockless(q) >= ATH10K_MAX_NUM_MGMT_PENDING) {
 		ath10k_warn(ar, "wmi mgmt tx queue is full\n");
-		ret = -ENOSPC;
-		goto unlock;
+		return -ENOSPC;
 	}
 
-	__skb_queue_tail(q, skb);
+	skb_queue_tail(q, skb);
 	ieee80211_queue_work(ar->hw, &ar->wmi_mgmt_tx_work);
 
-unlock:
-	spin_unlock_bh(&ar->data_lock);
-
-	return ret;
+	return 0;
 }
 
 static enum ath10k_mac_tx_path
-- 
2.27.0


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^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2021-02-24 12:51 UTC | newest]

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2021-02-24 12:49 [PATCH AUTOSEL 5.11 01/67] ath10k: prevent deinitializing NAPI twice Sasha Levin
2021-02-24 12:49 ` [PATCH AUTOSEL 5.11 14/67] ath10k: fix wmi mgmt tx queue full due to race condition Sasha Levin

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