ath11k: Fix napi related hang

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

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

@@ -175,8 +175,11 @@ static void __ath11k_ahb_ext_irq_disable(struct ath11k_base *ab)
 
 		ath11k_ahb_ext_grp_disable(irq_grp);
 
+		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(struct ath11k_base *ab)
 	for (i = 0; i < ATH11K_EXT_IRQ_GRP_NUM_MAX; i++) {
 		struct ath11k_ext_irq_grp *irq_grp = &ab->ext_irq_grp[i];
 
+		if (!irq_grp->napi_enabled) {
 			napi_enable(&irq_grp->napi);
+			irq_grp->napi_enabled = true;
+		}
 		ath11k_ahb_ext_grp_enable(irq_grp);
 	}
 }

drivers/net/wireless/ath/ath11k/core.h

@@ -142,6 +142,7 @@ 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;
 };
@@ -743,7 +744,6 @@ 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;

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

@@ -683,8 +683,11 @@ static void __ath11k_pci_ext_irq_disable(struct ath11k_base *sc)
 
 		ath11k_pci_ext_grp_disable(irq_grp);
 
+		if (irq_grp->napi_enabled) {
 			napi_synchronize(&irq_grp->napi);
 			napi_disable(&irq_grp->napi);
+			irq_grp->napi_enabled = false;
+		}
 	}
 }
 
@@ -712,7 +715,10 @@ static void ath11k_pci_ext_irq_enable(struct ath11k_base *ab)
 	for (i = 0; i < ATH11K_EXT_IRQ_GRP_NUM_MAX; i++) {
 		struct ath11k_ext_irq_grp *irq_grp = &ab->ext_irq_grp[i];
 
+		if (!irq_grp->napi_enabled) {
 			napi_enable(&irq_grp->napi);
+			irq_grp->napi_enabled = true;
+		}
 		ath11k_pci_ext_grp_enable(irq_grp);
 	}
 }