mt76: mt7615: improve mt7615_driver_own reliability

mt7615_driver_own can fail if it runs too close to mt7615_fw_own. In
order to improve mt7615_driver_own reliability, retry to get runtime-pm
ownership if mt7615_driver_own fails
Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

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

@@ -1891,29 +1891,36 @@ int mt7615_driver_own(struct mt7615_dev *dev)
 {
 	struct mt76_phy *mphy = &dev->mt76.phy;
 	struct mt76_dev *mdev = &dev->mt76;
-	int err = 0;
-	u32 addr;
+	int i;
 
 	if (!test_and_clear_bit(MT76_STATE_PM, &mphy->state))
 		goto out;
 
 	mt7622_trigger_hif_int(dev, true);
 
-	addr = is_mt7663(mdev) ? MT_PCIE_DOORBELL_PUSH : MT_CFG_LPCR_HOST;
-	mt76_wr(dev, addr, MT_CFG_LPCR_HOST_DRV_OWN);
+	for (i = 0; i < MT7615_DRV_OWN_RETRY_COUNT; i++) {
+		u32 addr;
 
-	addr = is_mt7663(mdev) ? MT_CONN_HIF_ON_LPCTL : MT_CFG_LPCR_HOST;
-	if (!mt76_poll_msec(dev, addr, MT_CFG_LPCR_HOST_FW_OWN, 0, 3000)) {
-		dev_err(mdev->dev, "Timeout for driver own\n");
-		set_bit(MT76_STATE_PM, &mphy->state);
-		err = -EIO;
+		addr = is_mt7663(mdev) ? MT_PCIE_DOORBELL_PUSH : MT_CFG_LPCR_HOST;
+		mt76_wr(dev, addr, MT_CFG_LPCR_HOST_DRV_OWN);
+
+		addr = is_mt7663(mdev) ? MT_CONN_HIF_ON_LPCTL : MT_CFG_LPCR_HOST;
+		if (mt76_poll_msec(dev, addr, MT_CFG_LPCR_HOST_FW_OWN, 0, 50))
+			break;
 	}
 
 	mt7622_trigger_hif_int(dev, false);
+
+	if (i == MT7615_DRV_OWN_RETRY_COUNT) {
+		dev_err(mdev->dev, "driver own failed\n");
+		set_bit(MT76_STATE_PM, &mphy->state);
+		return -EIO;
+	}
+
 out:
 	dev->pm.last_activity = jiffies;
 
-	return err;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(mt7615_driver_own);
 

drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h

@@ -33,6 +33,8 @@
 #define MT7615_RX_RING_SIZE		1024
 #define MT7615_RX_MCU_RING_SIZE		512
 
+#define MT7615_DRV_OWN_RETRY_COUNT	10
+
 #define MT7615_FIRMWARE_CR4		"mediatek/mt7615_cr4.bin"
 #define MT7615_FIRMWARE_N9		"mediatek/mt7615_n9.bin"
 #define MT7615_ROM_PATCH		"mediatek/mt7615_rom_patch.bin"