[PATCH v2 1/2] wifi: mt76: mt7921: add pci restore for hibernate

[Hedi Ben Hamida <hedihamida096@gmail.com>]

Hibernation powers the device off and on. On resume the generic restore
path runs the normal resume sequence and can time out waiting for the
hif-suspend MCU handshake:

  mt7921e 0000:03:00.0: Message 00020007 (seq 12) timeout
  mt7921e 0000:03:00.0: PM: dpm_run_callback(): pci_pm_restore returns -110

Add a dedicated .restore callback, mirroring mt7925, which skips the
handshake, resets the device and returns it to its pre-hibernate state.

Tested on MEDIATEK MT7922 (14c3:7922) on kernel 6.12.113.

Cc: stable@vger.kernel.org
Signed-off-by: Hedi Ben Hamida <hedihamida096@gmail.com>
---
 .../net/wireless/mediatek/mt76/mt7921/pci.c   | 26 ++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
index f87c44f2a..00532b29f 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
@@ -549,7 +549,7 @@ static int mt7921_pci_suspend(struct device *device)
 	return err;
 }
 
-static int mt7921_pci_resume(struct device *device)
+static int _mt7921_pci_resume(struct device *device, bool restore)
 {
 	struct pci_dev *pdev = to_pci_dev(device);
 	struct mt76_dev *mdev = pci_get_drvdata(pdev);
@@ -589,6 +589,9 @@ static int mt7921_pci_resume(struct device *device)
 	napi_schedule(&mdev->tx_napi);
 	local_bh_enable();
 
+	if (restore)
+		goto failed;
+
 	/* restore previous ds setting */
 	if (!pm->ds_enable)
 		mt76_connac_mcu_set_deep_sleep(&dev->mt76, false);
@@ -602,7 +605,7 @@ static int mt7921_pci_resume(struct device *device)
 failed:
 	pm->suspended = false;
 
-	if (err < 0)
+	if (err < 0 || restore)
 		mt792x_reset(&dev->mt76);
 
 	return err;
@@ -715,7 +718,24 @@ static void mt7921_pci_shutdown(struct pci_dev *pdev)
 	mt7921_pci_remove(pdev);
 }
 
-static DEFINE_SIMPLE_DEV_PM_OPS(mt7921_pm_ops, mt7921_pci_suspend, mt7921_pci_resume);
+static int mt7921_pci_resume(struct device *device)
+{
+	return _mt7921_pci_resume(device, false);
+}
+
+static int mt7921_pci_restore(struct device *device)
+{
+	return _mt7921_pci_resume(device, true);
+}
+
+static const struct dev_pm_ops mt7921_pm_ops = {
+	.suspend = pm_sleep_ptr(mt7921_pci_suspend),
+	.resume = pm_sleep_ptr(mt7921_pci_resume),
+	.freeze = pm_sleep_ptr(mt7921_pci_suspend),
+	.thaw = pm_sleep_ptr(mt7921_pci_resume),
+	.poweroff = pm_sleep_ptr(mt7921_pci_suspend),
+	.restore = pm_sleep_ptr(mt7921_pci_restore),
+};
 
 static struct pci_driver mt7921_pci_driver = {
 	.name		= KBUILD_MODNAME,
-- 
2.47.3