Re: [PATCH] mt76: mt7921: fix possible resume failure

Lorenzo Bianconi
2021-12-07T10:08:59Z

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> From: Sean Wang <sean.wang@mediatek.com>
>
> Fix the possible resume failure due to mt76_connac_mcu_set_hif_suspend
> timeout.
>
> That is because clearing the flag pm->suspended too early opened up a race
> window, where mt7921_poll_tx/rx scheduled a ps_work to put the device in
> doze mode, that is unexpected for the device is being resumed from the
> suspend state and would make the remaining MCU comamnds in resume handler
> failed to execute.

do we have a similar issue in mt7921s_resume()?

>
> Fixes: ffa1bf97425b ("mt76: mt7921: introduce PM 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>
> ---
> drivers/net/wireless/mediatek/mt76/mt7921/pci.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> index 5635de3c80b1..21a48f02ab60 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> @@ -315,7 +315,6 @@ static int mt7921_pci_resume(struct pci_dev *pdev)
> struct mt76_connac_pm *pm = &dev->pm;
> int i, err;
>
> - pm->suspended = false;
> err = pci_set_power_state(pdev, PCI_D0);
> if (err)
> return err;
> @@ -353,7 +352,11 @@ static int mt7921_pci_resume(struct pci_dev *pdev)
> if (!pm->ds_enable)
> mt76_connac_mcu_set_deep_sleep(&dev->mt76, false);
>
> - return mt76_connac_mcu_set_hif_suspend(mdev, false);
> + err = mt76_connac_mcu_set_hif_suspend(mdev, false);
> +
> + pm->suspended = false;
> +
> + return err;
> }
> #endif /* CONFIG_PM */
>
> --
> 2.25.1
>

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