mt76: mt7921s: fix the device cannot sleep deeply in suspend

According to the MT7921S firmware, the cmd MCU_UNI_CMD_HIF_CTRL have to
be last MCU command to execute in suspend handler and all data traffic
have to be stopped before the cmd MCU_UNI_CMD_HIF_CTRL starts as well
in order that mt7921 can successfully fall into the deep sleep mode.

Where we reuse the flag MT76_STATE_SUSPEND and avoid creating
another global flag to stop all of the traffic onto the SDIO bus.

Fixes: 48fab5bbef40 ("mt76: mt7921: introduce mt7921s support")
Reported-by: Leon Yen <leon.yen@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 22 insertions, 12 deletions

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
index 5fee489c7a99..5c88b6b8d097 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
@@ -206,6 +206,8 @@ static int mt7921s_suspend(struct device *__dev)
 	int err;
 
 	pm->suspended = true;
+	set_bit(MT76_STATE_SUSPEND, &mdev->phy.state);
+
 	cancel_delayed_work_sync(&pm->ps_work);
 	cancel_work_sync(&pm->wake_work);
 
@@ -213,10 +215,6 @@ static int mt7921s_suspend(struct device *__dev)
 	if (err < 0)
 		goto restore_suspend;
 
-	err = mt76_connac_mcu_set_hif_suspend(mdev, true);
-	if (err)
-		goto restore_suspend;
-
 	/* always enable deep sleep during suspend to reduce
 	 * power consumption
 	 */
@@ -224,34 +222,45 @@ static int mt7921s_suspend(struct device *__dev)
 
 	mt76_txq_schedule_all(&dev->mphy);
 	mt76_worker_disable(&mdev->tx_worker);
-	mt76_worker_disable(&mdev->sdio.txrx_worker);
 	mt76_worker_disable(&mdev->sdio.status_worker);
-	mt76_worker_disable(&mdev->sdio.net_worker);
 	cancel_work_sync(&mdev->sdio.stat_work);
 	clear_bit(MT76_READING_STATS, &dev->mphy.state);
-
 	mt76_tx_status_check(mdev, true);
 
-	err = mt7921_mcu_fw_pmctrl(dev);
+	mt76_worker_schedule(&mdev->sdio.txrx_worker);
+	wait_event_timeout(dev->mt76.sdio.wait,
+			   mt76s_txqs_empty(&dev->mt76), 5 * HZ);
+
+	/* It is supposed that SDIO bus is idle at the point */
+	err = mt76_connac_mcu_set_hif_suspend(mdev, true);
 	if (err)
 		goto restore_worker;
 
+	mt76_worker_disable(&mdev->sdio.txrx_worker);
+	mt76_worker_disable(&mdev->sdio.net_worker);
+
+	err = mt7921_mcu_fw_pmctrl(dev);
+	if (err)
+		goto restore_txrx_worker;
+
 	sdio_set_host_pm_flags(func, MMC_PM_KEEP_POWER);
 
 	return 0;
 
+restore_txrx_worker:
+	mt76_worker_enable(&mdev->sdio.net_worker);
+	mt76_worker_enable(&mdev->sdio.txrx_worker);
+	mt76_connac_mcu_set_hif_suspend(mdev, false);
+
 restore_worker:
 	mt76_worker_enable(&mdev->tx_worker);
-	mt76_worker_enable(&mdev->sdio.txrx_worker);
 	mt76_worker_enable(&mdev->sdio.status_worker);
-	mt76_worker_enable(&mdev->sdio.net_worker);
 
 	if (!pm->ds_enable)
 		mt76_connac_mcu_set_deep_sleep(mdev, false);
 
-	mt76_connac_mcu_set_hif_suspend(mdev, false);
-
 restore_suspend:
+	clear_bit(MT76_STATE_SUSPEND, &mdev->phy.state);
 	pm->suspended = false;
 
 	return err;
@@ -266,6 +275,7 @@ static int mt7921s_resume(struct device *__dev)
 	int err;
 
 	pm->suspended = false;
+	clear_bit(MT76_STATE_SUSPEND, &mdev->phy.state);
 
 	err = mt7921_mcu_drv_pmctrl(dev);
 	if (err < 0)