mt76: only iterate over initialized rx queues

Fixes the following reported crash:

[    2.361127] BUG: spinlock bad magic on CPU#0, modprobe/456
[    2.361583]  lock: 0xffffa1287525b3b8, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[    2.362250] CPU: 0 PID: 456 Comm: modprobe Not tainted 4.14.177 #5
[    2.362751] Hardware name: HP Meep/Meep, BIOS Google_Meep.11297.75.0 06/17/2019
[    2.363343] Call Trace:
[    2.363552]  dump_stack+0x97/0xdb
[    2.363826]  ? spin_bug+0xa6/0xb3
[    2.364096]  do_raw_spin_lock+0x6a/0x9a
[    2.364417]  mt76_dma_rx_fill+0x44/0x1de [mt76]
[    2.364787]  ? mt76_dma_kick_queue+0x18/0x18 [mt76]
[    2.365184]  mt76_dma_init+0x53/0x85 [mt76]
[    2.365532]  mt7615_dma_init+0x3d7/0x546 [mt7615e]
[    2.365928]  mt7615_register_device+0xe6/0x1a0 [mt7615e]
[    2.366364]  mt7615_mmio_probe+0x14b/0x171 [mt7615e]
[    2.366771]  mt7615_pci_probe+0x118/0x13b [mt7615e]
[    2.367169]  pci_device_probe+0xaf/0x13d
[    2.367491]  driver_probe_device+0x284/0x2ca
[    2.367840]  __driver_attach+0x7a/0x9e
[    2.368146]  ? driver_attach+0x1f/0x1f
[    2.368451]  bus_for_each_dev+0xa0/0xdb
[    2.368765]  bus_add_driver+0x132/0x204
[    2.369078]  driver_register+0x8e/0xcd
[    2.369384]  do_one_initcall+0x160/0x257
[    2.369706]  ? 0xffffffffc0240000
[    2.369980]  do_init_module+0x60/0x1bb
[    2.370286]  load_module+0x18c2/0x1a2b
[    2.370596]  ? kernel_read_file+0x141/0x1b9
[    2.370937]  ? kernel_read_file_from_fd+0x46/0x71
[    2.371320]  SyS_finit_module+0xcc/0xf0
[    2.371636]  do_syscall_64+0x6b/0xf7
[    2.371930]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[    2.372344] RIP: 0033:0x7da218ae4199
[    2.372637] RSP: 002b:00007fffd0608398 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[    2.373252] RAX: ffffffffffffffda RBX: 00005a705449df90 RCX: 00007da218ae4199
[    2.373833] RDX: 0000000000000000 RSI: 00005a7052e73bd8 RDI: 0000000000000006
[    2.374411] RBP: 00007fffd06083e0 R08: 0000000000000000 R09: 00005a705449d540
[    2.374989] R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000000
[    2.375569] R13: 00005a705449def0 R14: 00005a7052e73bd8 R15: 0000000000000000

Reported-by: Sean Wang <sean.wang@mediatek.com>
Fixes: d3377b78ce ("mt76: add HE phy modes and hardware queue")
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/debugfs.c

@@ -51,7 +51,7 @@ static int mt76_rx_queues_read(struct seq_file *s, void *data)
 	struct mt76_dev *dev = dev_get_drvdata(s->private);
 	int i, queued;
 
-	for (i = 0; i < ARRAY_SIZE(dev->q_rx); i++) {
+	mt76_for_each_q_rx(dev, i) {
 		struct mt76_queue *q = &dev->q_rx[i];
 
 		if (!q->ndesc)

drivers/net/wireless/mediatek/mt76/dma.c

@@ -576,7 +576,7 @@ mt76_dma_init(struct mt76_dev *dev)
 
 	init_dummy_netdev(&dev->napi_dev);
 
-	for (i = 0; i < ARRAY_SIZE(dev->q_rx); i++) {
+	mt76_for_each_q_rx(dev, i) {
 		netif_napi_add(&dev->napi_dev, &dev->napi[i], mt76_dma_rx_poll,
 			       64);
 		mt76_dma_rx_fill(dev, &dev->q_rx[i]);
@@ -610,7 +610,7 @@ void mt76_dma_cleanup(struct mt76_dev *dev)
 	for (i = 0; i < ARRAY_SIZE(dev->q_tx); i++)
 		mt76_dma_tx_cleanup(dev, i, true);
 
-	for (i = 0; i < ARRAY_SIZE(dev->q_rx); i++) {
+	mt76_for_each_q_rx(dev, i) {
 		netif_napi_del(&dev->napi[i]);
 		mt76_dma_rx_cleanup(dev, &dev->q_rx[i]);
 	}

drivers/net/wireless/mediatek/mt76/mt76.h

@@ -671,6 +671,10 @@ static inline u16 mt76_rev(struct mt76_dev *dev)
 #define mt76_queue_tx_cleanup(dev, ...)	(dev)->mt76.queue_ops->tx_cleanup(&((dev)->mt76), __VA_ARGS__)
 #define mt76_queue_kick(dev, ...)	(dev)->mt76.queue_ops->kick(&((dev)->mt76), __VA_ARGS__)
 
+#define mt76_for_each_q_rx(dev, i)	\
+	for (i = 0; i < ARRAY_SIZE((dev)->q_rx) && \
+		    (dev)->q_rx[i].ndesc; i++)
+
 struct mt76_dev *mt76_alloc_device(struct device *pdev, unsigned int size,
 				   const struct ieee80211_ops *ops,
 				   const struct mt76_driver_ops *drv_ops);

drivers/net/wireless/mediatek/mt76/mt7603/mac.c

@@ -1438,8 +1438,9 @@ static void mt7603_mac_watchdog_reset(struct mt7603_dev *dev)
 	for (i = 0; i < __MT_TXQ_MAX; i++)
 		mt76_queue_tx_cleanup(dev, i, true);
 
-	for (i = 0; i < ARRAY_SIZE(dev->mt76.q_rx); i++)
+	mt76_for_each_q_rx(&dev->mt76, i) {
 		mt76_queue_rx_reset(dev, i);
+	}
 
 	mt7603_dma_sched_reset(dev);
 

drivers/net/wireless/mediatek/mt76/mt7615/mac.c

@@ -1820,8 +1820,9 @@ void mt7615_dma_reset(struct mt7615_dev *dev)
 	for (i = 0; i < __MT_TXQ_MAX; i++)
 		mt76_queue_tx_cleanup(dev, i, true);
 
-	for (i = 0; i < ARRAY_SIZE(dev->mt76.q_rx); i++)
+	mt76_for_each_q_rx(&dev->mt76, i) {
 		mt76_queue_rx_reset(dev, i);
+	}
 
 	mt76_set(dev, MT_WPDMA_GLO_CFG,
 		 MT_WPDMA_GLO_CFG_RX_DMA_EN | MT_WPDMA_GLO_CFG_TX_DMA_EN |

drivers/net/wireless/mediatek/mt76/mt7615/pci.c

@@ -86,8 +86,9 @@ static int mt7615_pci_suspend(struct pci_dev *pdev, pm_message_t state)
 	napi_disable(&mdev->tx_napi);
 	tasklet_kill(&mdev->tx_tasklet);
 
-	for (i = 0; i < ARRAY_SIZE(mdev->q_rx); i++)
+	mt76_for_each_q_rx(mdev, i) {
 		napi_disable(&mdev->napi[i]);
+	}
 	tasklet_kill(&dev->irq_tasklet);
 
 	mt7615_dma_reset(dev);
@@ -120,8 +121,9 @@ static int mt7615_pci_suspend(struct pci_dev *pdev, pm_message_t state)
 	return 0;
 
 restore:
-	for (i = 0; i < ARRAY_SIZE(mdev->q_rx); i++)
+	mt76_for_each_q_rx(mdev, i) {
 		napi_enable(&mdev->napi[i]);
+	}
 	napi_enable(&mdev->tx_napi);
 	if (hif_suspend)
 		mt7615_mcu_set_hif_suspend(dev, false);
@@ -156,7 +158,7 @@ static int mt7615_pci_resume(struct pci_dev *pdev)
 	if (pdma_reset)
 		dev_err(mdev->dev, "PDMA engine must be reinitialized\n");
 
-	for (i = 0; i < ARRAY_SIZE(mdev->q_rx); i++) {
+	mt76_for_each_q_rx(mdev, i) {
 		napi_enable(&mdev->napi[i]);
 		napi_schedule(&mdev->napi[i]);
 	}

drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c

@@ -489,8 +489,9 @@ static void mt76x02_watchdog_reset(struct mt76x02_dev *dev)
 	for (i = 0; i < __MT_TXQ_MAX; i++)
 		mt76_queue_tx_cleanup(dev, i, true);
 
-	for (i = 0; i < ARRAY_SIZE(dev->mt76.q_rx); i++)
+	mt76_for_each_q_rx(&dev->mt76, i) {
 		mt76_queue_rx_reset(dev, i);
+	}
 
 	mt76x02_mac_start(dev);
 

drivers/net/wireless/mediatek/mt76/mt7915/mac.c

@@ -1146,8 +1146,9 @@ mt7915_dma_reset(struct mt7915_dev *dev)
 	for (i = 0; i < __MT_TXQ_MAX; i++)
 		mt76_queue_tx_cleanup(dev, i, true);
 
-	for (i = 0; i < ARRAY_SIZE(dev->mt76.q_rx); i++)
+	mt76_for_each_q_rx(&dev->mt76, i) {
 		mt76_queue_rx_reset(dev, i);
+	}
 
 	/* re-init prefetch settings after reset */
 	mt7915_dma_prefetch(dev);