[RFC 2/2] wifi: mt76: mt7996: Clean up IRQ on module unload.

[greearb@candelatech.com]

From: Ben Greear <greearb@candelatech.com>

When removing mt7996e module, softirqd would go to 100%
cpu usage.  It appears the problem is lack of cleanup of
the irq objects and proper kill of the irq_tasklet.

Clean these up, similar to how the error cleanup path works
in mt7996_pci_probe.

Signed-off-by: Ben Greear <greearb@candelatech.com>
---

NOTE:  Tested in 7.2 + modifications kernel, but applies and compiles
against 7.3 linus tree.  Not tested there at this point.

 drivers/net/wireless/mediatek/mt76/mt7996/init.c | 16 +++++++++++++++-
 .../net/wireless/mediatek/mt76/mt7996/mt7996.h   |  1 +
 drivers/net/wireless/mediatek/mt76/mt7996/pci.c  | 11 +++++++++--
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/init.c b/drivers/net/wireless/mediatek/mt76/mt7996/init.c
index fb635a092584..45fc76cecd04 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/init.c
@@ -1807,6 +1807,18 @@ int mt7996_register_device(struct mt7996_dev *dev)
 	return ret;
 }
 
+static void mt7996_cleanup_irqs(struct mt7996_dev *dev)
+{
+	struct mt76_dev *mdev = &dev->mt76;
+	struct pci_dev *pdev = to_pci_dev(mdev->dev);
+
+	mt7996_put_hif2(dev, dev->hif2); /* frees hif2 irq */
+
+	devm_free_irq(mdev->dev, pdev->irq, dev);
+	if (!mtk_wed_device_active(&dev->mt76.mmio.wed))
+		pci_free_irq_vectors(pdev);
+}
+
 void mt7996_unregister_device(struct mt7996_dev *dev)
 {
 	cancel_work_sync(&dev->dump_work);
@@ -1825,7 +1837,9 @@ void mt7996_unregister_device(struct mt7996_dev *dev)
 	if (mt7996_has_hwrro(dev) &&
 	    !mtk_wed_device_active(&dev->mt76.mmio.wed))
 		mt7996_rro_msdu_page_map_free(dev);
-	tasklet_disable(&dev->mt76.irq_tasklet);
+	tasklet_kill(&dev->mt76.irq_tasklet);
+
+	mt7996_cleanup_irqs(dev);
 
 	mt76_free_device(&dev->mt76);
 }
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h b/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
index 2a0cdb56f822..79c57e88e107 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
@@ -678,6 +678,7 @@ irqreturn_t mt7996_irq_handler(int irq, void *dev_instance);
 u64 __mt7996_get_tsf(struct ieee80211_hw *hw, struct mt7996_vif_link *link);
 int mt7996_register_device(struct mt7996_dev *dev);
 void mt7996_unregister_device(struct mt7996_dev *dev);
+void mt7996_put_hif2(struct mt7996_dev *dev, struct mt7996_hif *hif);
 int mt7996_vif_link_add(struct mt76_phy *mphy, struct ieee80211_vif *vif,
 			struct ieee80211_bss_conf *link_conf,
 			struct mt76_vif_link *mlink);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/pci.c b/drivers/net/wireless/mediatek/mt76/mt7996/pci.c
index b7d9193e042f..5c686cf66d0a 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/pci.c
@@ -53,11 +53,19 @@ static struct mt7996_hif *mt7996_pci_get_hif2(u32 idx)
 	return hif;
 }
 
-static void mt7996_put_hif2(struct mt7996_hif *hif)
+void mt7996_put_hif2(struct mt7996_dev *dev, struct mt7996_hif *hif)
 {
+	struct pci_dev *hif2_dev;
+
 	if (!hif)
 		return;
 
+	hif2_dev = container_of(hif->dev, struct pci_dev, dev);
+
+	devm_free_irq(dev->mt76.dev, hif->irq, dev);
+	if (!mtk_wed_device_active(&dev->mt76.mmio.wed_hif2))
+		pci_free_irq_vectors(hif2_dev);
+
 	put_device(hif->dev);
 }
 
@@ -237,7 +245,6 @@ static void mt7996_pci_remove(struct pci_dev *pdev)
 
 	mdev = pci_get_drvdata(pdev);
 	dev = container_of(mdev, struct mt7996_dev, mt76);
-	mt7996_put_hif2(dev->hif2);
 	mt7996_unregister_device(dev);
 }
 
-- 
2.42.0