[PATCH net-next] net: stmmac: Fix sparse warning

[PATCH net-next] net: stmmac: Fix sparse warning

[Jose Abreu]

The VID is converted to le16 so the variable must be __le16 type.

Reported-by: kbuild test robot <lkp@intel.com>
Fixes: c7ab0b8088d7 ("net: stmmac: Fallback to VLAN Perfect filtering if HASH is not available")
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>

---
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Jose Abreu <joabreu@synopsys.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: netdev@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c   | 2 +-
 drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c | 2 +-
 drivers/net/ethernet/stmicro/stmmac/hwif.h          | 2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c   | 5 +++--
 4 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index df11376ee735..090ebceb288a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -733,7 +733,7 @@ static void dwmac4_set_mac_loopback(void __iomem *ioaddr, bool enable)
 }
 
 static void dwmac4_update_vlan_hash(struct mac_device_info *hw, u32 hash,
-				    u16 perfect_match, bool is_double)
+				    __le16 perfect_match, bool is_double)
 {
 	void __iomem *ioaddr = hw->pcsr;
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
index 5cda360d5d07..e24382d00e62 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
@@ -555,7 +555,7 @@ static int dwxgmac2_rss_configure(struct mac_device_info *hw,
 }
 
 static void dwxgmac2_update_vlan_hash(struct mac_device_info *hw, u32 hash,
-				      u16 perfect_match, bool is_double)
+				      __le16 perfect_match, bool is_double)
 {
 	void __iomem *ioaddr = hw->pcsr;
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 1303d1e9a18f..509daeefdb79 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -357,7 +357,7 @@ struct stmmac_ops {
 			     struct stmmac_rss *cfg, u32 num_rxq);
 	/* VLAN */
 	void (*update_vlan_hash)(struct mac_device_info *hw, u32 hash,
-				 u16 perfect_match, bool is_double);
+				 __le16 perfect_match, bool is_double);
 	void (*enable_vlan)(struct mac_device_info *hw, u32 type);
 	/* TX Timestamp */
 	int (*get_mac_tx_timestamp)(struct mac_device_info *hw, u64 *ts);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 8b76745a7ec4..40b0756f3a14 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4207,6 +4207,7 @@ static u32 stmmac_vid_crc32_le(__le16 vid_le)
 static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
 {
 	u32 crc, hash = 0;
+	__le16 pmatch = 0;
 	int count = 0;
 	u16 vid = 0;
 
@@ -4221,11 +4222,11 @@ static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
 		if (count > 2) /* VID = 0 always passes filter */
 			return -EOPNOTSUPP;
 
-		vid = cpu_to_le16(vid);
+		pmatch = cpu_to_le16(vid);
 		hash = 0;
 	}
 
-	return stmmac_update_vlan_hash(priv, priv->hw, hash, vid, is_double);
+	return stmmac_update_vlan_hash(priv, priv->hw, hash, pmatch, is_double);
 }
 
 static int stmmac_vlan_rx_add_vid(struct net_device *ndev, __be16 proto, u16 vid)
-- 
2.7.4

Re: [PATCH net-next] net: stmmac: Fix sparse warning

[David Miller]

From: Jose Abreu <Jose.Abreu@synopsys.com>
Date: Mon,  7 Oct 2019 15:16:08 +0200

> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 8b76745a7ec4..40b0756f3a14 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -4207,6 +4207,7 @@ static u32 stmmac_vid_crc32_le(__le16 vid_le)
>  static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
>  {
>  	u32 crc, hash = 0;
> +	__le16 pmatch = 0;
>  	int count = 0;
>  	u16 vid = 0;
>  
> @@ -4221,11 +4222,11 @@ static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
>  		if (count > 2) /* VID = 0 always passes filter */
>  			return -EOPNOTSUPP;
>  
> -		vid = cpu_to_le16(vid);
> +		pmatch = cpu_to_le16(vid);
>  		hash = 0;
>  	}
>  
> -	return stmmac_update_vlan_hash(priv, priv->hw, hash, vid, is_double);
> +	return stmmac_update_vlan_hash(priv, priv->hw, hash, pmatch, is_double);
>  }

I dunno about this.

The original code would use the last "vid" iterated over in the
for_each_set_bit() loop if the priv->dma_cap.vlhash test does not
pass.

Now, it will use zero in that case.

This does not look like an equivalent transformation.

RE: [PATCH net-next] net: stmmac: Fix sparse warning

[Jose Abreu]

From: David Miller <davem@davemloft.net>
Date: Oct/07/2019, 15:14:26 (UTC+00:00)

> From: Jose Abreu <Jose.Abreu@synopsys.com>
> Date: Mon,  7 Oct 2019 15:16:08 +0200
> 
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > index 8b76745a7ec4..40b0756f3a14 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > @@ -4207,6 +4207,7 @@ static u32 stmmac_vid_crc32_le(__le16 vid_le)
> >  static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
> >  {
> >  	u32 crc, hash = 0;
> > +	__le16 pmatch = 0;
> >  	int count = 0;
> >  	u16 vid = 0;
> >  
> > @@ -4221,11 +4222,11 @@ static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
> >  		if (count > 2) /* VID = 0 always passes filter */
> >  			return -EOPNOTSUPP;
> >  
> > -		vid = cpu_to_le16(vid);
> > +		pmatch = cpu_to_le16(vid);
> >  		hash = 0;
> >  	}
> >  
> > -	return stmmac_update_vlan_hash(priv, priv->hw, hash, vid, is_double);
> > +	return stmmac_update_vlan_hash(priv, priv->hw, hash, pmatch, is_double);
> >  }
> 
> I dunno about this.
> 
> The original code would use the last "vid" iterated over in the
> for_each_set_bit() loop if the priv->dma_cap.vlhash test does not
> pass.
> 
> Now, it will use zero in that case.
> 
> This does not look like an equivalent transformation.

It is intended behavior. HW specific callbacks: 
dwmac4_update_vlan_hash() / dwxgmac2_update_vlan_hash(), will either use 
Hash method or Perfect method so if priv->dma_cap.vlhash is not 
available then pmatch will be last vid. Otherwise, it will be zero and 
hash will be populated.

---
Thanks,
Jose Miguel Abreu