[PATCH (net.git) 0/3] stmmac MDIO and normal descr fixes

[PATCH (net.git) 0/3] stmmac MDIO and normal descr fixes

[Giuseppe Cavallaro]

This patch series is to fix the problems below and recently debugged
in this mailing list:

o to fix a problem for the HW where the normal descriptor
o to fix the mdio registration according to the different
  platform configurations

I am resending all the patches again: built on top of net.git repo.

Giuseppe Cavallaro (3):
  stmmac: fix TX normal DESC
  Revert "stmmac: Fix 'eth0: No PHY found' regression"
  stmmac: fix MDIO settings

 drivers/net/ethernet/stmicro/stmmac/norm_desc.c    |   16 ++--
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  |   16 +---
 drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  |   10 +--
 .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |   91 ++++++++++++++------
 include/linux/stmmac.h                             |    1 -
 5 files changed, 80 insertions(+), 54 deletions(-)

-- 
1.7.4.4

[PATCH (net.git) 1/3] stmmac: fix TX normal DESC

[Giuseppe Cavallaro]

This patch fixs a regression raised when test on chips that use
the normal descriptor layout. In fact, no len bits were set for
the TDES1 and no OWN bit inside the TDES0.

Signed-off-by: Giuseppe CAVALLARO <peppe.cavallaro@st.com>
Tested-by: Andreas Färber <afaerber@suse.de>
Cc: Fabrice Gasnier <fabrice.gasnier@st.com>
---
 drivers/net/ethernet/stmicro/stmmac/norm_desc.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
index e13228f..011386f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
@@ -199,11 +199,6 @@ static void ndesc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
 {
 	unsigned int tdes1 = p->des1;
 
-	if (mode == STMMAC_CHAIN_MODE)
-		norm_set_tx_desc_len_on_chain(p, len);
-	else
-		norm_set_tx_desc_len_on_ring(p, len);
-
 	if (is_fs)
 		tdes1 |= TDES1_FIRST_SEGMENT;
 	else
@@ -217,10 +212,15 @@ static void ndesc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
 	if (ls)
 		tdes1 |= TDES1_LAST_SEGMENT;
 
-	if (tx_own)
-		tdes1 |= TDES0_OWN;
-
 	p->des1 = tdes1;
+
+	if (mode == STMMAC_CHAIN_MODE)
+		norm_set_tx_desc_len_on_chain(p, len);
+	else
+		norm_set_tx_desc_len_on_ring(p, len);
+
+	if (tx_own)
+		p->des0 |= TDES0_OWN;
 }
 
 static void ndesc_set_tx_ic(struct dma_desc *p)
-- 
1.7.4.4

[PATCH (net.git) 2/3] Revert "stmmac: Fix 'eth0: No PHY found' regression"

[Giuseppe Cavallaro]

This reverts commit 88f8b1bb41c6208f81b6a480244533ded7b59493.
due to problems on GeekBox and Banana Pi M1 board when
connected to a real transceiver instead of a switch via
fixed-link.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Gabriel Fernandez <gabriel.fernandez@linaro.org>
Cc: Andreas Färber <afaerber@suse.de>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Cc: Dinh Nguyen <dinh.linux@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  |   11 ++++++++++-
 .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |    9 +--------
 include/linux/stmmac.h                             |    1 -
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index ea76129..af09ced 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -199,12 +199,21 @@ int stmmac_mdio_register(struct net_device *ndev)
 	struct stmmac_priv *priv = netdev_priv(ndev);
 	struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
 	int addr, found;
-	struct device_node *mdio_node = priv->plat->mdio_node;
+	struct device_node *mdio_node = NULL;
+	struct device_node *child_node = NULL;
 
 	if (!mdio_bus_data)
 		return 0;
 
 	if (IS_ENABLED(CONFIG_OF)) {
+		for_each_child_of_node(priv->device->of_node, child_node) {
+			if (of_device_is_compatible(child_node,
+						    "snps,dwmac-mdio")) {
+				mdio_node = child_node;
+				break;
+			}
+		}
+
 		if (mdio_node) {
 			netdev_dbg(ndev, "FOUND MDIO subnode\n");
 		} else {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index dcbd2a1..9cf181f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -146,7 +146,6 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 	struct device_node *np = pdev->dev.of_node;
 	struct plat_stmmacenet_data *plat;
 	struct stmmac_dma_cfg *dma_cfg;
-	struct device_node *child_node = NULL;
 
 	plat = devm_kzalloc(&pdev->dev, sizeof(*plat), GFP_KERNEL);
 	if (!plat)
@@ -177,19 +176,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 		plat->phy_node = of_node_get(np);
 	}
 
-	for_each_child_of_node(np, child_node)
-		if (of_device_is_compatible(child_node,	"snps,dwmac-mdio")) {
-			plat->mdio_node = child_node;
-			break;
-		}
-
 	/* "snps,phy-addr" is not a standard property. Mark it as deprecated
 	 * and warn of its use. Remove this when phy node support is added.
 	 */
 	if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr) == 0)
 		dev_warn(&pdev->dev, "snps,phy-addr property is deprecated\n");
 
-	if ((plat->phy_node && !of_phy_is_fixed_link(np)) || !plat->mdio_node)
+	if ((plat->phy_node && !of_phy_is_fixed_link(np)) || plat->phy_bus_name)
 		plat->mdio_bus_data = NULL;
 	else
 		plat->mdio_bus_data =
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 4bcf5a6..6e53fa8 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -114,7 +114,6 @@ struct plat_stmmacenet_data {
 	int interface;
 	struct stmmac_mdio_bus_data *mdio_bus_data;
 	struct device_node *phy_node;
-	struct device_node *mdio_node;
 	struct stmmac_dma_cfg *dma_cfg;
 	int clk_csr;
 	int has_gmac;
-- 
1.7.4.4

Re: [PATCH (net.git) 2/3] Revert "stmmac: Fix 'eth0: No PHY found' regression"

[Marc Haber]

On Fri, Apr 01, 2016 at 09:07:15AM +0200, Giuseppe Cavallaro wrote:
> This reverts commit 88f8b1bb41c6208f81b6a480244533ded7b59493.
> due to problems on GeekBox and Banana Pi M1 board when
> connected to a real transceiver instead of a switch via
> fixed-link.

This reversal is still needed in Linux 4.5.1 on Banana Pi.

Please consider including it in Linux 4.5.2.

Greetings
Marc

> 
> Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
> Cc: Gabriel Fernandez <gabriel.fernandez@linaro.org>
> Cc: Andreas Färber <afaerber@suse.de>
> Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
> Cc: Dinh Nguyen <dinh.linux@gmail.com>
> Cc: David S. Miller <davem@davemloft.net>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  |   11 ++++++++++-
>  .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |    9 +--------
>  include/linux/stmmac.h                             |    1 -
>  3 files changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> index ea76129..af09ced 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> @@ -199,12 +199,21 @@ int stmmac_mdio_register(struct net_device *ndev)
>  	struct stmmac_priv *priv = netdev_priv(ndev);
>  	struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
>  	int addr, found;
> -	struct device_node *mdio_node = priv->plat->mdio_node;
> +	struct device_node *mdio_node = NULL;
> +	struct device_node *child_node = NULL;
>  
>  	if (!mdio_bus_data)
>  		return 0;
>  
>  	if (IS_ENABLED(CONFIG_OF)) {
> +		for_each_child_of_node(priv->device->of_node, child_node) {
> +			if (of_device_is_compatible(child_node,
> +						    "snps,dwmac-mdio")) {
> +				mdio_node = child_node;
> +				break;
> +			}
> +		}
> +
>  		if (mdio_node) {
>  			netdev_dbg(ndev, "FOUND MDIO subnode\n");
>  		} else {
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index dcbd2a1..9cf181f 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -146,7 +146,6 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>  	struct device_node *np = pdev->dev.of_node;
>  	struct plat_stmmacenet_data *plat;
>  	struct stmmac_dma_cfg *dma_cfg;
> -	struct device_node *child_node = NULL;
>  
>  	plat = devm_kzalloc(&pdev->dev, sizeof(*plat), GFP_KERNEL);
>  	if (!plat)
> @@ -177,19 +176,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>  		plat->phy_node = of_node_get(np);
>  	}
>  
> -	for_each_child_of_node(np, child_node)
> -		if (of_device_is_compatible(child_node,	"snps,dwmac-mdio")) {
> -			plat->mdio_node = child_node;
> -			break;
> -		}
> -
>  	/* "snps,phy-addr" is not a standard property. Mark it as deprecated
>  	 * and warn of its use. Remove this when phy node support is added.
>  	 */
>  	if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr) == 0)
>  		dev_warn(&pdev->dev, "snps,phy-addr property is deprecated\n");
>  
> -	if ((plat->phy_node && !of_phy_is_fixed_link(np)) || !plat->mdio_node)
> +	if ((plat->phy_node && !of_phy_is_fixed_link(np)) || plat->phy_bus_name)
>  		plat->mdio_bus_data = NULL;
>  	else
>  		plat->mdio_bus_data =
> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
> index 4bcf5a6..6e53fa8 100644
> --- a/include/linux/stmmac.h
> +++ b/include/linux/stmmac.h
> @@ -114,7 +114,6 @@ struct plat_stmmacenet_data {
>  	int interface;
>  	struct stmmac_mdio_bus_data *mdio_bus_data;
>  	struct device_node *phy_node;
> -	struct device_node *mdio_node;
>  	struct stmmac_dma_cfg *dma_cfg;
>  	int clk_csr;
>  	int has_gmac;
> -- 
> 1.7.4.4
> 

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

Re: [PATCH (net.git) 2/3] Revert "stmmac: Fix 'eth0: No PHY found' regression"

[Marc Haber]

On Wed, Apr 13, 2016 at 05:44:25PM +0200, Marc Haber wrote:
> On Fri, Apr 01, 2016 at 09:07:15AM +0200, Giuseppe Cavallaro wrote:
> > This reverts commit 88f8b1bb41c6208f81b6a480244533ded7b59493.
> > due to problems on GeekBox and Banana Pi M1 board when
> > connected to a real transceiver instead of a switch via
> > fixed-link.
> 
> This reversal is still needed in Linux 4.5.1 on Banana Pi.
> 
> Please consider including it in Linux 4.5.2.

This reversal is still needed in Linux 4.5.4 on Banana Pi.

Please consider including it in Linux 4.5.5.

Greetings
Marc



> 
> > 
> > Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
> > Cc: Gabriel Fernandez <gabriel.fernandez@linaro.org>
> > Cc: Andreas Färber <afaerber@suse.de>
> > Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
> > Cc: Dinh Nguyen <dinh.linux@gmail.com>
> > Cc: David S. Miller <davem@davemloft.net>
> > ---
> >  drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  |   11 ++++++++++-
> >  .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |    9 +--------
> >  include/linux/stmmac.h                             |    1 -
> >  3 files changed, 11 insertions(+), 10 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> > index ea76129..af09ced 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> > @@ -199,12 +199,21 @@ int stmmac_mdio_register(struct net_device *ndev)
> >  	struct stmmac_priv *priv = netdev_priv(ndev);
> >  	struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
> >  	int addr, found;
> > -	struct device_node *mdio_node = priv->plat->mdio_node;
> > +	struct device_node *mdio_node = NULL;
> > +	struct device_node *child_node = NULL;
> >  
> >  	if (!mdio_bus_data)
> >  		return 0;
> >  
> >  	if (IS_ENABLED(CONFIG_OF)) {
> > +		for_each_child_of_node(priv->device->of_node, child_node) {
> > +			if (of_device_is_compatible(child_node,
> > +						    "snps,dwmac-mdio")) {
> > +				mdio_node = child_node;
> > +				break;
> > +			}
> > +		}
> > +
> >  		if (mdio_node) {
> >  			netdev_dbg(ndev, "FOUND MDIO subnode\n");
> >  		} else {
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > index dcbd2a1..9cf181f 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > @@ -146,7 +146,6 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
> >  	struct device_node *np = pdev->dev.of_node;
> >  	struct plat_stmmacenet_data *plat;
> >  	struct stmmac_dma_cfg *dma_cfg;
> > -	struct device_node *child_node = NULL;
> >  
> >  	plat = devm_kzalloc(&pdev->dev, sizeof(*plat), GFP_KERNEL);
> >  	if (!plat)
> > @@ -177,19 +176,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
> >  		plat->phy_node = of_node_get(np);
> >  	}
> >  
> > -	for_each_child_of_node(np, child_node)
> > -		if (of_device_is_compatible(child_node,	"snps,dwmac-mdio")) {
> > -			plat->mdio_node = child_node;
> > -			break;
> > -		}
> > -
> >  	/* "snps,phy-addr" is not a standard property. Mark it as deprecated
> >  	 * and warn of its use. Remove this when phy node support is added.
> >  	 */
> >  	if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr) == 0)
> >  		dev_warn(&pdev->dev, "snps,phy-addr property is deprecated\n");
> >  
> > -	if ((plat->phy_node && !of_phy_is_fixed_link(np)) || !plat->mdio_node)
> > +	if ((plat->phy_node && !of_phy_is_fixed_link(np)) || plat->phy_bus_name)
> >  		plat->mdio_bus_data = NULL;
> >  	else
> >  		plat->mdio_bus_data =
> > diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
> > index 4bcf5a6..6e53fa8 100644
> > --- a/include/linux/stmmac.h
> > +++ b/include/linux/stmmac.h
> > @@ -114,7 +114,6 @@ struct plat_stmmacenet_data {
> >  	int interface;
> >  	struct stmmac_mdio_bus_data *mdio_bus_data;
> >  	struct device_node *phy_node;
> > -	struct device_node *mdio_node;
> >  	struct stmmac_dma_cfg *dma_cfg;
> >  	int clk_csr;
> >  	int has_gmac;
> > -- 
> > 1.7.4.4
> > 
> 
> -- 
> -----------------------------------------------------------------------------
> Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
> Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
> Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

[PATCH (net.git) 3/3] stmmac: fix MDIO settings

[Giuseppe Cavallaro]

Initially the phy_bus_name was added to manipulate the
driver name but it was recently just used to manage the
fixed-link and then to take some decision at run-time.
So the patch uses the is_pseudo_fixed_link and removes
the phy_bus_name variable not necessary anymore.

The driver can manage the mdio registration by using phy-handle,
dwmac-mdio and own parameter e.g. snps,phy-addr.
This patch takes care about all these possible configurations
and fixes the mdio registration in case of there is a real
transceiver or a switch (that needs to be managed by using
fixed-link).

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Tested-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Cc: Gabriel Fernandez <gabriel.fernandez@linaro.org>
Cc: Dinh Nguyen <dinh.linux@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Phil Reid <preid@electromag.com.au>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  |   16 +---
 drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  |   19 +----
 .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |   84 +++++++++++++++----
 include/linux/stmmac.h                             |    2 +-
 4 files changed, 73 insertions(+), 48 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 4c5ce98..78464fa 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -278,7 +278,6 @@ static void stmmac_eee_ctrl_timer(unsigned long arg)
  */
 bool stmmac_eee_init(struct stmmac_priv *priv)
 {
-	char *phy_bus_name = priv->plat->phy_bus_name;
 	unsigned long flags;
 	bool ret = false;
 
@@ -290,7 +289,7 @@ bool stmmac_eee_init(struct stmmac_priv *priv)
 		goto out;
 
 	/* Never init EEE in case of a switch is attached */
-	if (phy_bus_name && (!strcmp(phy_bus_name, "fixed")))
+	if (priv->phydev->is_pseudo_fixed_link)
 		goto out;
 
 	/* MAC core supports the EEE feature. */
@@ -827,12 +826,8 @@ static int stmmac_init_phy(struct net_device *dev)
 		phydev = of_phy_connect(dev, priv->plat->phy_node,
 					&stmmac_adjust_link, 0, interface);
 	} else {
-		if (priv->plat->phy_bus_name)
-			snprintf(bus_id, MII_BUS_ID_SIZE, "%s-%x",
-				 priv->plat->phy_bus_name, priv->plat->bus_id);
-		else
-			snprintf(bus_id, MII_BUS_ID_SIZE, "stmmac-%x",
-				 priv->plat->bus_id);
+		snprintf(bus_id, MII_BUS_ID_SIZE, "stmmac-%x",
+			 priv->plat->bus_id);
 
 		snprintf(phy_id_fmt, MII_BUS_ID_SIZE + 3, PHY_ID_FMT, bus_id,
 			 priv->plat->phy_addr);
@@ -871,9 +866,8 @@ static int stmmac_init_phy(struct net_device *dev)
 	}
 
 	/* If attached to a switch, there is no reason to poll phy handler */
-	if (priv->plat->phy_bus_name)
-		if (!strcmp(priv->plat->phy_bus_name, "fixed"))
-			phydev->irq = PHY_IGNORE_INTERRUPT;
+	if (phydev->is_pseudo_fixed_link)
+		phydev->irq = PHY_IGNORE_INTERRUPT;
 
 	pr_debug("stmmac_init_phy:  %s: attached to PHY (UID 0x%x)"
 		 " Link = %d\n", dev->name, phydev->phy_id, phydev->link);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index af09ced..06704ca 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -198,29 +198,12 @@ int stmmac_mdio_register(struct net_device *ndev)
 	struct mii_bus *new_bus;
 	struct stmmac_priv *priv = netdev_priv(ndev);
 	struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
+	struct device_node *mdio_node = priv->plat->mdio_node;
 	int addr, found;
-	struct device_node *mdio_node = NULL;
-	struct device_node *child_node = NULL;
 
 	if (!mdio_bus_data)
 		return 0;
 
-	if (IS_ENABLED(CONFIG_OF)) {
-		for_each_child_of_node(priv->device->of_node, child_node) {
-			if (of_device_is_compatible(child_node,
-						    "snps,dwmac-mdio")) {
-				mdio_node = child_node;
-				break;
-			}
-		}
-
-		if (mdio_node) {
-			netdev_dbg(ndev, "FOUND MDIO subnode\n");
-		} else {
-			netdev_warn(ndev, "No MDIO subnode found\n");
-		}
-	}
-
 	new_bus = mdiobus_alloc();
 	if (new_bus == NULL)
 		return -ENOMEM;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 9cf181f..cf37ea5 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -132,6 +132,69 @@ static struct stmmac_axi *stmmac_axi_setup(struct platform_device *pdev)
 }
 
 /**
+ * stmmac_dt_phy - parse device-tree driver parameters to allocate PHY resources
+ * @plat: driver data platform structure
+ * @np: device tree node
+ * @dev: device pointer
+ * Description:
+ * The mdio bus will be allocated in case of a phy transceiver is on board;
+ * it will be NULL if the fixed-link is configured.
+ * If there is the "snps,dwmac-mdio" sub-node the mdio will be allocated
+ * in any case (for DSA, mdio must be registered even if fixed-link).
+ * The table below sums the supported configurations:
+ *	-------------------------------
+ *	snps,phy-addr	|     Y
+ *	-------------------------------
+ *	phy-handle	|     Y
+ *	-------------------------------
+ *	fixed-link	|     N
+ *	-------------------------------
+ *	snps,dwmac-mdio	|
+ *	  even if	|     Y
+ *	fixed-link	|
+ *	-------------------------------
+ *
+ * It returns 0 in case of success otherwise -ENODEV.
+ */
+static int stmmac_dt_phy(struct plat_stmmacenet_data *plat,
+			 struct device_node *np, struct device *dev)
+{
+	bool mdio = true;
+
+	/* If phy-handle property is passed from DT, use it as the PHY */
+	plat->phy_node = of_parse_phandle(np, "phy-handle", 0);
+	if (plat->phy_node)
+		dev_dbg(dev, "Found phy-handle subnode\n");
+
+	/* If phy-handle is not specified, check if we have a fixed-phy */
+	if (!plat->phy_node && of_phy_is_fixed_link(np)) {
+		if ((of_phy_register_fixed_link(np) < 0))
+			return -ENODEV;
+
+		dev_dbg(dev, "Found fixed-link subnode\n");
+		plat->phy_node = of_node_get(np);
+		mdio = false;
+	}
+
+	/* If snps,dwmac-mdio is passed from DT, always register the MDIO */
+	for_each_child_of_node(np, plat->mdio_node) {
+		if (of_device_is_compatible(plat->mdio_node, "snps,dwmac-mdio"))
+			break;
+	}
+
+	if (plat->mdio_node) {
+		dev_dbg(dev, "Found MDIO subnode\n");
+		mdio = true;
+	}
+
+	if (mdio)
+		plat->mdio_bus_data =
+			devm_kzalloc(dev, sizeof(struct stmmac_mdio_bus_data),
+				     GFP_KERNEL);
+	return 0;
+}
+
+/**
  * stmmac_probe_config_dt - parse device-tree driver parameters
  * @pdev: platform_device structure
  * @plat: driver data platform structure
@@ -165,30 +228,15 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 	/* Default to phy auto-detection */
 	plat->phy_addr = -1;
 
-	/* If we find a phy-handle property, use it as the PHY */
-	plat->phy_node = of_parse_phandle(np, "phy-handle", 0);
-
-	/* If phy-handle is not specified, check if we have a fixed-phy */
-	if (!plat->phy_node && of_phy_is_fixed_link(np)) {
-		if ((of_phy_register_fixed_link(np) < 0))
-			return ERR_PTR(-ENODEV);
-
-		plat->phy_node = of_node_get(np);
-	}
-
 	/* "snps,phy-addr" is not a standard property. Mark it as deprecated
 	 * and warn of its use. Remove this when phy node support is added.
 	 */
 	if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr) == 0)
 		dev_warn(&pdev->dev, "snps,phy-addr property is deprecated\n");
 
-	if ((plat->phy_node && !of_phy_is_fixed_link(np)) || plat->phy_bus_name)
-		plat->mdio_bus_data = NULL;
-	else
-		plat->mdio_bus_data =
-			devm_kzalloc(&pdev->dev,
-				     sizeof(struct stmmac_mdio_bus_data),
-				     GFP_KERNEL);
+	/* To Configure PHY by using all device-tree supported properties */
+	if (stmmac_dt_phy(plat, np, &pdev->dev))
+		return ERR_PTR(-ENODEV);
 
 	of_property_read_u32(np, "tx-fifo-depth", &plat->tx_fifo_size);
 
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 6e53fa8..e6bc30a 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -108,12 +108,12 @@ struct stmmac_axi {
 };
 
 struct plat_stmmacenet_data {
-	char *phy_bus_name;
 	int bus_id;
 	int phy_addr;
 	int interface;
 	struct stmmac_mdio_bus_data *mdio_bus_data;
 	struct device_node *phy_node;
+	struct device_node *mdio_node;
 	struct stmmac_dma_cfg *dma_cfg;
 	int clk_csr;
 	int has_gmac;
-- 
1.7.4.4

Re: [PATCH (net.git) 0/3] stmmac MDIO and normal descr fixes

[David Miller]

From: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Date: Fri, 1 Apr 2016 09:07:13 +0200

> This patch series is to fix the problems below and recently debugged
> in this mailing list:
> 
> o to fix a problem for the HW where the normal descriptor
> o to fix the mdio registration according to the different
>   platform configurations
> 
> I am resending all the patches again: built on top of net.git repo.

Series applied, thanks.