Subject: Re: [PATCH v2 net-next 5/5] net: ethernet: mtk_wed: add reset/reset_complete callbacks

From: Lorenzo Bianconi <[email-masked]>
Date: Wed, 4 Jan 2023 15:59:17 +0100

> On Wed, Jan 04, 2023 at 03:03:14PM +0100, Lorenzo Bianconi wrote:
> > Introduce reset and reset_complete wlan callback to schedule WLAN driver
> > reset when ethernet/wed driver is resetting.
> > 
> > Tested-by: Daniel Golle <[email-masked]>
> > Co-developed-by: Sujuan Chen <[email-masked]>
> > Signed-off-by: Sujuan Chen <[email-masked]>
> > Signed-off-by: Lorenzo Bianconi <[email-masked]>
> > ---
> >  drivers/net/ethernet/mediatek/mtk_eth_soc.c |  6 ++++
> >  drivers/net/ethernet/mediatek/mtk_wed.c     | 40 +++++++++++++++++++++
> >  drivers/net/ethernet/mediatek/mtk_wed.h     |  8 +++++
> >  include/linux/soc/mediatek/mtk_wed.h        |  2 ++
> >  4 files changed, 56 insertions(+)
> > 
> > diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> > index bafae4f0312e..2d74e26f45c9 100644
> > --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> > +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> > @@ -3913,6 +3913,10 @@ static void mtk_pending_work(struct work_struct *work)
> >  		mtk_w32(eth, val, MTK_MAC_MCR(i));
> >  	}
> >  
> > +	rtnl_unlock();
> > +	mtk_wed_fe_reset();
> > +	rtnl_lock();
> 
> Is it safe to call rtnl_unlock(), perform some work and lock again?

Yes, mtk_pending_work sets MTK_RESETTING bit and a new reset work is not
scheduled until this bit is cleared

> 
> > +
> >  	/* stop all devices to make sure that dma is properly shut down */
> >  	for (i = 0; i < MTK_MAC_COUNT; i++) {
> >  		if (!eth->netdev[i] || !netif_running(eth->netdev[i]))
> > @@ -3949,6 +3953,8 @@ static void mtk_pending_work(struct work_struct *work)
> >  
> >  	clear_bit(MTK_RESETTING, &eth->state);
> >  
> > +	mtk_wed_fe_reset_complete();
> > +
> >  	rtnl_unlock();
> >  }
> >  
> > diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
> > index a6271449617f..4854993f2941 100644
> > --- a/drivers/net/ethernet/mediatek/mtk_wed.c
> > +++ b/drivers/net/ethernet/mediatek/mtk_wed.c
> > @@ -206,6 +206,46 @@ mtk_wed_wo_reset(struct mtk_wed_device *dev)
> >  	iounmap(reg);
> >  }
> >  
> > +void mtk_wed_fe_reset(void)
> > +{
> > +	int i;
> > +
> > +	mutex_lock(&hw_lock);
> > +
> > +	for (i = 0; i < ARRAY_SIZE(hw_list); i++) {
> > +		struct mtk_wed_hw *hw = hw_list[i];
> > +		struct mtk_wed_device *dev = hw->wed_dev;
> > +
> > +		if (!dev || !dev->wlan.reset)
> > +			continue;
> > +
> > +		/* reset callback blocks until WLAN reset is completed */
> > +		if (dev->wlan.reset(dev))
> > +			dev_err(dev->dev, "wlan reset failed\n");
> > +	}
> > +
> > +	mutex_unlock(&hw_lock);
> > +}
> > +
> > +void mtk_wed_fe_reset_complete(void)
> > +{
> > +	int i;
> > +
> > +	mutex_lock(&hw_lock);
> > +
> > +	for (i = 0; i < ARRAY_SIZE(hw_list); i++) {
> > +		struct mtk_wed_hw *hw = hw_list[i];
> > +		struct mtk_wed_device *dev = hw->wed_dev;
> > +
> > +		if (!dev || !dev->wlan.reset_complete)
> > +			continue;
> > +
> > +		dev->wlan.reset_complete(dev);
> > +	}
> > +
> > +	mutex_unlock(&hw_lock);
> > +}
> > +
> >  static struct mtk_wed_hw *
> >  mtk_wed_assign(struct mtk_wed_device *dev)
> >  {
> > diff --git a/drivers/net/ethernet/mediatek/mtk_wed.h b/drivers/net/ethernet/mediatek/mtk_wed.h
> > index e012b8a82133..6108a7e69a80 100644
> > --- a/drivers/net/ethernet/mediatek/mtk_wed.h
> > +++ b/drivers/net/ethernet/mediatek/mtk_wed.h
> > @@ -128,6 +128,8 @@ void mtk_wed_add_hw(struct device_node *np, struct mtk_eth *eth,
> >  void mtk_wed_exit(void);
> >  int mtk_wed_flow_add(int index);
> >  void mtk_wed_flow_remove(int index);
> > +void mtk_wed_fe_reset(void);
> > +void mtk_wed_fe_reset_complete(void);
> >  #else
> >  static inline void
> >  mtk_wed_add_hw(struct device_node *np, struct mtk_eth *eth,
> > @@ -146,6 +148,12 @@ static inline int mtk_wed_flow_add(int index)
> >  static inline void mtk_wed_flow_remove(int index)
> >  {
> >  }
> > +static inline void mtk_wed_fe_reset(void)
> > +{
> > +}
> > +static inline void mtk_wed_fe_reset_complete(void)
> > +{
> > +}
> >  
> >  #endif
> >  
> > diff --git a/include/linux/soc/mediatek/mtk_wed.h b/include/linux/soc/mediatek/mtk_wed.h
> > index db637a13888d..ddff54fc9717 100644
> > --- a/include/linux/soc/mediatek/mtk_wed.h
> > +++ b/include/linux/soc/mediatek/mtk_wed.h
> > @@ -150,6 +150,8 @@ struct mtk_wed_device {
> >  		void (*release_rx_buf)(struct mtk_wed_device *wed);
> >  		void (*update_wo_rx_stats)(struct mtk_wed_device *wed,
> >  					   struct mtk_wed_wo_rx_stats *stats);
> > +		int (*reset)(struct mtk_wed_device *wed);
> > +		int (*reset_complete)(struct mtk_wed_device *wed);
> 
> I don't see any driver implementation of these callbacks in this series.
> Did I miss it?

These callbacks are implemented in the mt76 driver. I have not added these
patches to the series since mt76 patches usually go through Felix/Kalle's
trees (anyway I am fine to add them to the series if they can go into net-next
directly).

Regards,
Lorenzo

> Thanks
> >  	} wlan;
> >  #endif
> >  };
> > -- 
> > 2.39.0