wifi: mt76: mt7921s: fix race issue between reset and suspend/resume

It is unexpected that the reset work is running simultaneously with
the suspend or resume context and it is possible that reset work is still
running even after mt7921 is suspended if we don't fix the race issue.

Thus, the suspend procedure should be waiting until the reset is completed
at the beginning and ignore the subsequent the reset requests.

In case there is an error that happens during either suspend or resume
handler, we will schedule a reset task to recover the error before
returning the error code to ensure we can immediately fix the error there.

Fixes: ca74b9b907f9 ("mt76: mt7921s: add reset support")
Co-developed-by: YN Chen <YN.Chen@mediatek.com>
Signed-off-by: YN Chen <YN.Chen@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
index 487acd6e2be8fd031e6d697b178b73f17deba94e..2face849fb4fba15c864929c6b2e9a81cb06b07c 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
@@ -206,6 +206,7 @@ static int mt7921s_suspend(struct device *__dev)
        pm->suspended = true;
        set_bit(MT76_STATE_SUSPEND, &mdev->phy.state);
 
+       flush_work(&dev->reset_work);
        cancel_delayed_work_sync(&pm->ps_work);
        cancel_work_sync(&pm->wake_work);
 
@@ -261,6 +262,9 @@ restore_suspend:
        clear_bit(MT76_STATE_SUSPEND, &mdev->phy.state);
        pm->suspended = false;
 
+       if (err < 0)
+               mt7921_reset(&dev->mt76);
+
        return err;
 }
 
@@ -276,7 +280,7 @@ static int mt7921s_resume(struct device *__dev)
 
        err = mt7921_mcu_drv_pmctrl(dev);
        if (err < 0)
-               return err;
+               goto failed;
 
        mt76_worker_enable(&mdev->tx_worker);
        mt76_worker_enable(&mdev->sdio.txrx_worker);
@@ -288,11 +292,12 @@ static int mt7921s_resume(struct device *__dev)
                mt76_connac_mcu_set_deep_sleep(mdev, false);
 
        err = mt76_connac_mcu_set_hif_suspend(mdev, false);
-       if (err)
-               return err;
-
+failed:
        pm->suspended = false;
 
+       if (err < 0)
+               mt7921_reset(&dev->mt76);
+
        return err;
 }