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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Ben Greear <greearb@candelatech.com>,
        Kalle Valo <quic_kvalo@quicinc.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 0689/1039] ath11k: Fix napi related hang
Date:   Mon, 24 Jan 2022 19:41:18 +0100
Message-Id: <20220124184148.509793510@linuxfoundation.org>
In-Reply-To: <20220124184125.121143506@linuxfoundation.org>
References: <20220124184125.121143506@linuxfoundation.org>
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From: Ben Greear <greearb@candelatech.com>

[ Upstream commit d943fdad7589653065be0e20aadc6dff37725ed4 ]

Similar to the same bug in ath10k, a napi disable w/out it being enabled
will hang forever.  I believe I saw this while trying rmmod after driver
had some failure on startup.  Fix it by keeping state on whether napi is
enabled or not.

And, remove un-used napi pointer in ath11k driver base struct.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20200903195254.29379-1-greearb@candelatech.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/ath/ath11k/ahb.c  |   12 +++++++++---
 drivers/net/wireless/ath/ath11k/core.h |    2 +-
 drivers/net/wireless/ath/ath11k/pci.c  |   12 +++++++++---
 3 files changed, 19 insertions(+), 7 deletions(-)

--- a/drivers/net/wireless/ath/ath11k/ahb.c
+++ b/drivers/net/wireless/ath/ath11k/ahb.c
@@ -175,8 +175,11 @@ static void __ath11k_ahb_ext_irq_disable
 
 		ath11k_ahb_ext_grp_disable(irq_grp);
 
-		napi_synchronize(&irq_grp->napi);
-		napi_disable(&irq_grp->napi);
+		if (irq_grp->napi_enabled) {
+			napi_synchronize(&irq_grp->napi);
+			napi_disable(&irq_grp->napi);
+			irq_grp->napi_enabled = false;
+		}
 	}
 }
 
@@ -300,7 +303,10 @@ static void ath11k_ahb_ext_irq_enable(st
 	for (i = 0; i < ATH11K_EXT_IRQ_GRP_NUM_MAX; i++) {
 		struct ath11k_ext_irq_grp *irq_grp = &ab->ext_irq_grp[i];
 
-		napi_enable(&irq_grp->napi);
+		if (!irq_grp->napi_enabled) {
+			napi_enable(&irq_grp->napi);
+			irq_grp->napi_enabled = true;
+		}
 		ath11k_ahb_ext_grp_enable(irq_grp);
 	}
 }
--- a/drivers/net/wireless/ath/ath11k/core.h
+++ b/drivers/net/wireless/ath/ath11k/core.h
@@ -141,6 +141,7 @@ struct ath11k_ext_irq_grp {
 	u32 num_irq;
 	u32 grp_id;
 	u64 timestamp;
+	bool napi_enabled;
 	struct napi_struct napi;
 	struct net_device napi_ndev;
 };
@@ -718,7 +719,6 @@ struct ath11k_base {
 	u32 wlan_init_status;
 	int irq_num[ATH11K_IRQ_NUM_MAX];
 	struct ath11k_ext_irq_grp ext_irq_grp[ATH11K_EXT_IRQ_GRP_NUM_MAX];
-	struct napi_struct *napi;
 	struct ath11k_targ_cap target_caps;
 	u32 ext_service_bitmap[WMI_SERVICE_EXT_BM_SIZE];
 	bool pdevs_macaddr_valid;
--- a/drivers/net/wireless/ath/ath11k/pci.c
+++ b/drivers/net/wireless/ath/ath11k/pci.c
@@ -638,8 +638,11 @@ static void __ath11k_pci_ext_irq_disable
 
 		ath11k_pci_ext_grp_disable(irq_grp);
 
-		napi_synchronize(&irq_grp->napi);
-		napi_disable(&irq_grp->napi);
+		if (irq_grp->napi_enabled) {
+			napi_synchronize(&irq_grp->napi);
+			napi_disable(&irq_grp->napi);
+			irq_grp->napi_enabled = false;
+		}
 	}
 }
 
@@ -658,7 +661,10 @@ static void ath11k_pci_ext_irq_enable(st
 	for (i = 0; i < ATH11K_EXT_IRQ_GRP_NUM_MAX; i++) {
 		struct ath11k_ext_irq_grp *irq_grp = &ab->ext_irq_grp[i];
 
-		napi_enable(&irq_grp->napi);
+		if (!irq_grp->napi_enabled) {
+			napi_enable(&irq_grp->napi);
+			irq_grp->napi_enabled = true;
+		}
 		ath11k_pci_ext_grp_enable(irq_grp);
 	}
 }