Re: [PATCH 2/2] mt76: mt7921s: fix the device cannot sleep deeply in suspend

[Lorenzo Bianconi <lorenzo@kernel.org>]

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> From: Sean Wang <sean.wang@mediatek.com>
> 
> 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>
> ---
>  .../wireless/mediatek/mt76/mt76_connac_mcu.c  |  2 +-
>  .../net/wireless/mediatek/mt76/mt7921/main.c  |  3 --
>  .../net/wireless/mediatek/mt76/mt7921/sdio.c  | 34 ++++++++++++-------
>  drivers/net/wireless/mediatek/mt76/sdio.c     |  3 +-
>  .../net/wireless/mediatek/mt76/sdio_txrx.c    |  3 +-
>  5 files changed, 27 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
> index 26b4b875dcc0..61c4c86e79c8 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
> @@ -2461,7 +2461,7 @@ void mt76_connac_mcu_set_suspend_iter(void *priv, u8 *mac,
>  				      struct ieee80211_vif *vif)
>  {
>  	struct mt76_phy *phy = priv;
> -	bool suspend = test_bit(MT76_STATE_SUSPEND, &phy->state);
> +	bool suspend = !test_bit(MT76_STATE_RUNNING, &phy->state);
>  	struct ieee80211_hw *hw = phy->hw;
>  	struct cfg80211_wowlan *wowlan = hw->wiphy->wowlan_config;
>  	int i;
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/main.c b/drivers/net/wireless/mediatek/mt76/mt7921/main.c
> index e022251b4006..0b2a6b7f22ea 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7921/main.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7921/main.c
> @@ -1242,8 +1242,6 @@ static int mt7921_suspend(struct ieee80211_hw *hw,
>  	mt7921_mutex_acquire(dev);
>  
>  	clear_bit(MT76_STATE_RUNNING, &phy->mt76->state);
> -
> -	set_bit(MT76_STATE_SUSPEND, &phy->mt76->state);
>  	ieee80211_iterate_active_interfaces(hw,
>  					    IEEE80211_IFACE_ITER_RESUME_ALL,
>  					    mt76_connac_mcu_set_suspend_iter,
> @@ -1262,7 +1260,6 @@ static int mt7921_resume(struct ieee80211_hw *hw)
>  	mt7921_mutex_acquire(dev);
>  
>  	set_bit(MT76_STATE_RUNNING, &phy->mt76->state);
> -	clear_bit(MT76_STATE_SUSPEND, &phy->mt76->state);
>  	ieee80211_iterate_active_interfaces(hw,
>  					    IEEE80211_IFACE_ITER_RESUME_ALL,
>  					    mt76_connac_mcu_set_suspend_iter,
> 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);

I guess mt76_worker_disable() is supposed to do it, right?
I guess we can assume txrx_worker is no longer running here, right?

> +	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)
> diff --git a/drivers/net/wireless/mediatek/mt76/sdio.c b/drivers/net/wireless/mediatek/mt76/sdio.c
> index c99acc21225e..b0bc7be0fb1f 100644
> --- a/drivers/net/wireless/mediatek/mt76/sdio.c
> +++ b/drivers/net/wireless/mediatek/mt76/sdio.c
> @@ -479,7 +479,8 @@ static void mt76s_status_worker(struct mt76_worker *w)
>  			resched = true;
>  
>  		if (dev->drv->tx_status_data &&
> -		    !test_and_set_bit(MT76_READING_STATS, &dev->phy.state))
> +		    !test_and_set_bit(MT76_READING_STATS, &dev->phy.state) &&
> +		    !test_bit(MT76_STATE_SUSPEND, &dev->phy.state))
>  			queue_work(dev->wq, &dev->sdio.stat_work);
>  	} while (nframes > 0);
>  
> diff --git a/drivers/net/wireless/mediatek/mt76/sdio_txrx.c b/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
> index 649a56790b89..801590a0a334 100644
> --- a/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
> +++ b/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
> @@ -317,7 +317,8 @@ void mt76s_txrx_worker(struct mt76_sdio *sdio)
>  		if (ret > 0)
>  			nframes += ret;
>  
> -		if (test_bit(MT76_MCU_RESET, &dev->phy.state)) {
> +		if (test_bit(MT76_MCU_RESET, &dev->phy.state) ||
> +		    test_bit(MT76_STATE_SUSPEND, &dev->phy.state)) {
>  			if (!mt76s_txqs_empty(dev))
>  				continue;
>  			else

since mt76s_tx_run_queue will not run if MT76_MCU_RESET is set, do we really
need to check it for each iteration or is fine something like:

diff --git a/drivers/net/wireless/mediatek/mt76/sdio_txrx.c b/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
index 649a56790b89..68f30a83fa5d 100644
--- a/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
+++ b/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
@@ -317,14 +317,12 @@ void mt76s_txrx_worker(struct mt76_sdio *sdio)
 		if (ret > 0)
 			nframes += ret;
 
-		if (test_bit(MT76_MCU_RESET, &dev->phy.state)) {
-			if (!mt76s_txqs_empty(dev))
-				continue;
-			else
-				wake_up(&sdio->wait);
-		}
 	} while (nframes > 0);
 
+	if (test_bit(MT76_MCU_RESET, &dev->phy.state) &&
+	    mt76s_txqs_empty(dev))
+		wake_up(&sdio->wait);
+
 	/* enable interrupt */
 	sdio_writel(sdio->func, WHLPCR_INT_EN_SET, MCR_WHLPCR, NULL);
 	sdio_release_host(sdio->func);

Regards,
Lorenzo

> -- 
> 2.25.1
> 

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