[PATCH] wifi: mt76: mt792x: fix scheduler interference in drv own process

[Mingyen Hsieh]

From: Michael Lo <michael.lo at mediatek.com>

Add some time to wait for LP engine to complete its operation
before polling pmctrl register.

Signed-off-by: Michael Lo <michael.lo at mediatek.com>
Signed-off-by: Ming Yen Hsieh <mingyen.hsieh at mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mt7921/pci.c  | 3 +++
 drivers/net/wireless/mediatek/mt76/mt7925/pci.c  | 3 +++
 drivers/net/wireless/mediatek/mt76/mt792x.h      | 1 +
 drivers/net/wireless/mediatek/mt76/mt792x_core.c | 6 ++++++
 4 files changed, 13 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
index f768e9389ac6..0f7d5a92f3d0 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
@@ -339,6 +339,9 @@ static int mt7921_pci_probe(struct pci_dev *pdev,
 	bus_ops->rmw = mt7921_rmw;
 	dev->mt76.bus = bus_ops;
 
+	if (mt7921_disable_aspm)
+		dev->disable_aspm = true;
+
 	ret = mt792xe_mcu_fw_pmctrl(dev);
 	if (ret)
 		goto err_free_dev;
diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/pci.c b/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
index 07b74d492ce1..e7039e312538 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
@@ -373,6 +373,9 @@ static int mt7925_pci_probe(struct pci_dev *pdev,
 	bus_ops->rmw = mt7925_rmw;
 	dev->mt76.bus = bus_ops;
 
+	if (mt7925_disable_aspm)
+		dev->disable_aspm = true;
+
 	ret = __mt792x_mcu_fw_pmctrl(dev);
 	if (ret)
 		goto err_free_dev;
diff --git a/drivers/net/wireless/mediatek/mt76/mt792x.h b/drivers/net/wireless/mediatek/mt76/mt792x.h
index 20578497a405..8f913336a668 100644
--- a/drivers/net/wireless/mediatek/mt76/mt792x.h
+++ b/drivers/net/wireless/mediatek/mt76/mt792x.h
@@ -190,6 +190,7 @@ struct mt792x_dev {
 	bool fw_assert:1;
 	bool has_eht:1;
 	bool regd_in_progress:1;
+	bool disable_aspm:1;
 	wait_queue_head_t wait;
 
 	struct work_struct init_work;
diff --git a/drivers/net/wireless/mediatek/mt76/mt792x_core.c b/drivers/net/wireless/mediatek/mt76/mt792x_core.c
index a405af8d9052..a11e5438a36e 100644
--- a/drivers/net/wireless/mediatek/mt76/mt792x_core.c
+++ b/drivers/net/wireless/mediatek/mt76/mt792x_core.c
@@ -766,6 +766,12 @@ int __mt792xe_mcu_drv_pmctrl(struct mt792x_dev *dev)
 
 	for (i = 0; i < MT792x_DRV_OWN_RETRY_COUNT; i++) {
 		mt76_wr(dev, MT_CONN_ON_LPCTL, PCIE_LPCR_HOST_CLR_OWN);
+
+		if (!dev->disable_aspm) {
+			/* wait for LP engine to complete its operation */
+			usleep_range(2000, 3000);
+		}
+
 		if (mt76_poll_msec_tick(dev, MT_CONN_ON_LPCTL,
 					PCIE_LPCR_HOST_OWN_SYNC, 0, 50, 1))
 			break;
-- 
2.25.1