[PATCH] wifi: mt76: mt7921e: introduce reboot notifier support

[Deren Wu <Deren.Wu@xxxxxxxxxxxx>]

From: Leon Yen <Leon.Yen@xxxxxxxxxxxx>

Some combinations of hosts cannnot detect mt7921e after reboot. The
interoperability issue is caused by the status mismatch between host
and chip fw. In such cases, the driver should stop chip activities
and reset chip to default state before reboot.

Co-developed-by: Deren Wu <deren.wu@xxxxxxxxxxxx>
Signed-off-by: Deren Wu <deren.wu@xxxxxxxxxxxx>
Signed-off-by: Leon Yen <Leon.Yen@xxxxxxxxxxxx>
---
 .../wireless/mediatek/mt76/mt7921/mt7921.h    |  1 +
 .../net/wireless/mediatek/mt76/mt7921/pci.c   | 25 +++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h b/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h
index 6fc04ed34ec3..64156d32b62d 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h
@@ -306,6 +306,7 @@ struct mt7921_dev {
 	struct sk_buff_head ipv6_ns_list;
 
 	enum environment_cap country_ie_env;
+	struct notifier_block reboot_nb;
 };
 
 enum {
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
index 28342ec940f0..6d20b3ed5db1 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
@@ -6,6 +6,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/reboot.h>
 
 #include "mt7921.h"
 #include "mac.h"
@@ -110,6 +111,7 @@ static void mt7921e_unregister_device(struct mt7921_dev *dev)
 	struct mt76_connac_pm *pm = &dev->pm;
 
 	cancel_work_sync(&dev->init_work);
+	unregister_reboot_notifier(&dev->reboot_nb);
 	mt76_unregister_device(&dev->mt76);
 	mt76_for_each_q_rx(&dev->mt76, i)
 		napi_disable(&dev->mt76.napi[i]);
@@ -226,6 +228,24 @@ static u32 mt7921_rmw(struct mt76_dev *mdev, u32 offset, u32 mask, u32 val)
 	return dev->bus_ops->rmw(mdev, addr, mask, val);
 }
 
+static int mt7921e_reboot_notifier(struct notifier_block *nb,
+				   unsigned long code, void *unused)
+{
+	struct mt7921_dev *dev = container_of(nb, struct mt7921_dev,
+					      reboot_nb);
+	struct mt76_connac_pm *pm = &dev->pm;
+
+	cancel_delayed_work_sync(&pm->ps_work);
+	cancel_work_sync(&pm->wake_work);
+
+	/* chip cleanup before reboot */
+	mt7921_mcu_drv_pmctrl(dev);
+	mt7921_dma_cleanup(dev);
+	mt7921_wfsys_reset(dev);
+
+	return NOTIFY_DONE;
+}
+
 static int mt7921_pci_probe(struct pci_dev *pdev,
 			    const struct pci_device_id *id)
 {
@@ -361,6 +381,11 @@ static int mt7921_pci_probe(struct pci_dev *pdev,
 	if (ret)
 		goto err_free_irq;
 
+	dev->reboot_nb.notifier_call = mt7921e_reboot_notifier;
+	ret = register_reboot_notifier(&dev->reboot_nb);
+	if (ret)
+		goto err_free_irq;
+
 	return 0;
 
 err_free_irq:
-- 
2.18.0