[PATCH v3 0/3] net/phy: micrel: Center FLP timing at 16ms

[PATCH v3 0/3] net/phy: micrel: Center FLP timing at 16ms

[Jaeden Amero]

In v2, we add an additional cleanup commit to make an array of strings
static const and to improve const correctness generally. We also no longer
unnecessarily initialize the result variable in
ksz9031_center_flp_timing().

In v3, we remove the unnecessary result variable from ksz9031_config_init()
introduced by a previous version of "net/phy: micrel: Center FLP timing at
16ms".

Jaeden Amero (3):
  net/phy: micrel: Be more const correct
  net/phy: micrel: Comment MMD address of extended registers
  net/phy: micrel: Center FLP timing at 16ms

 drivers/net/phy/micrel.c | 53 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 38 insertions(+), 15 deletions(-)

-- 
2.1.4

[PATCH v3 1/3] net/phy: micrel: Be more const correct

[Jaeden Amero]

In a few places in this driver, we weren't using const where we could
have. Use const more.

In addition, change the arrays of strings in ksz9031_config_init() to be
not only const, but also static.

Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
---
 drivers/net/phy/micrel.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index ebdc357..59cc5d4 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -288,9 +288,10 @@ static int kszphy_config_init(struct phy_device *phydev)
 }
 
 static int ksz9021_load_values_from_of(struct phy_device *phydev,
-				       struct device_node *of_node, u16 reg,
-				       char *field1, char *field2,
-				       char *field3, char *field4)
+				       const struct device_node *of_node,
+				       u16 reg,
+				       const char *field1, const char *field2,
+				       const char *field3, const char *field4)
 {
 	int val1 = -1;
 	int val2 = -2;
@@ -336,8 +337,8 @@ static int ksz9021_load_values_from_of(struct phy_device *phydev,
 
 static int ksz9021_config_init(struct phy_device *phydev)
 {
-	struct device *dev = &phydev->dev;
-	struct device_node *of_node = dev->of_node;
+	const struct device *dev = &phydev->dev;
+	const struct device_node *of_node = dev->of_node;
 
 	if (!of_node && dev->parent->of_node)
 		of_node = dev->parent->of_node;
@@ -389,9 +390,9 @@ static int ksz9031_extended_read(struct phy_device *phydev,
 }
 
 static int ksz9031_of_load_skew_values(struct phy_device *phydev,
-				       struct device_node *of_node,
+				       const struct device_node *of_node,
 				       u16 reg, size_t field_sz,
-				       char *field[], u8 numfields)
+				       const char *field[], u8 numfields)
 {
 	int val[4] = {-1, -2, -3, -4};
 	int matches = 0;
@@ -427,18 +428,18 @@ static int ksz9031_of_load_skew_values(struct phy_device *phydev,
 
 static int ksz9031_config_init(struct phy_device *phydev)
 {
-	struct device *dev = &phydev->dev;
-	struct device_node *of_node = dev->of_node;
-	char *clk_skews[2] = {"rxc-skew-ps", "txc-skew-ps"};
-	char *rx_data_skews[4] = {
+	const struct device *dev = &phydev->dev;
+	const struct device_node *of_node = dev->of_node;
+	static const char *clk_skews[2] = {"rxc-skew-ps", "txc-skew-ps"};
+	static const char *rx_data_skews[4] = {
 		"rxd0-skew-ps", "rxd1-skew-ps",
 		"rxd2-skew-ps", "rxd3-skew-ps"
 	};
-	char *tx_data_skews[4] = {
+	static const char *tx_data_skews[4] = {
 		"txd0-skew-ps", "txd1-skew-ps",
 		"txd2-skew-ps", "txd3-skew-ps"
 	};
-	char *control_skews[2] = {"txen-skew-ps", "rxdv-skew-ps"};
+	static const char *control_skews[2] = {"txen-skew-ps", "rxdv-skew-ps"};
 
 	if (!of_node && dev->parent->of_node)
 		of_node = dev->parent->of_node;
@@ -519,7 +520,7 @@ ksz9021_wr_mmd_phyreg(struct phy_device *phydev, int ptrad, int devnum,
 static int kszphy_probe(struct phy_device *phydev)
 {
 	const struct kszphy_type *type = phydev->drv->driver_data;
-	struct device_node *np = phydev->dev.of_node;
+	const struct device_node *np = phydev->dev.of_node;
 	struct kszphy_priv *priv;
 	struct clk *clk;
 	int ret;
-- 
2.1.4

[PATCH v3 2/3] net/phy: micrel: Comment MMD address of extended registers

[Jaeden Amero]

There are some defines for a few pad skew related extended registers.
Specify for which MMD Address (dev_addr) they are for.

Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
---
 drivers/net/phy/micrel.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 59cc5d4..f23765e 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -366,6 +366,7 @@ static int ksz9021_config_init(struct phy_device *phydev)
 #define KSZ9031_PS_TO_REG		60
 
 /* Extended registers */
+/* MMD Address 0x2 */
 #define MII_KSZ9031RN_CONTROL_PAD_SKEW	4
 #define MII_KSZ9031RN_RX_DATA_PAD_SKEW	5
 #define MII_KSZ9031RN_TX_DATA_PAD_SKEW	6
-- 
2.1.4

[PATCH v3 3/3] net/phy: micrel: Center FLP timing at 16ms

[Jaeden Amero]

Link failures have been observed when using the KSZ9031 with HP 1810-8G
and HP 1910-8G network switches. Center the FLP timing at 16ms to help
avoid intermittent link failures.

>From the KSZ9031RNX and KSZ9031MNX data sheets revision 2.2, section
"Auto-Negotiation Timing":
	The KSZ9031[RNX or MNX] Fast Link Pulse (FLP) burst-to-burst
	transmit timing for Auto-Negotiation defaults to 8ms. IEEE 802.3
	Standard specifies this timing to be 16ms +/-8ms. Some PHY link
	partners need to receive the FLP with 16ms centered timing;
	otherwise, there can be intermittent link failures and long
	link-up times.

	After KSZ9031[RNX or MNX] power-up/reset, program the following
	register sequence to set the FLP timing to 16ms

	Write Register Dh = 0x0000 // Set up register address for MMD – Device Address 0h
	Write Register Eh = 0x0004 // Select Register 4h of MMD – Device Address 0h
	Write Register Dh = 0x4000 // Select register data for MMD – Device Address 0h, Register 4h
	Write Register Eh = 0x0006 // Write value 0x0006 to MMD – Device Address 0h, Register 4h
	Write Register Dh = 0x0000 // Set up register address for MMD – Device Address 0h
	Write Register Eh = 0x0003 // Select Register 3h of MMD – Device Address 0h
	Write Register Dh = 0x4000 // Select register data for MMD – Device Address 0h, Register 3h
	Write Register Eh = 0x1A80 // Write value 0x1A80 to MMD – Device Address 0h, Register 3h
	Write Register 0h, Bit [9] = 1 // Restart Auto-Negotiation

Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
---
 drivers/net/phy/micrel.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index f23765e..499185e 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -366,6 +366,10 @@ static int ksz9021_config_init(struct phy_device *phydev)
 #define KSZ9031_PS_TO_REG		60
 
 /* Extended registers */
+/* MMD Address 0x0 */
+#define MII_KSZ9031RN_FLP_BURST_TX_LO	3
+#define MII_KSZ9031RN_FLP_BURST_TX_HI	4
+
 /* MMD Address 0x2 */
 #define MII_KSZ9031RN_CONTROL_PAD_SKEW	4
 #define MII_KSZ9031RN_RX_DATA_PAD_SKEW	5
@@ -427,6 +431,22 @@ static int ksz9031_of_load_skew_values(struct phy_device *phydev,
 	return ksz9031_extended_write(phydev, OP_DATA, 2, reg, newval);
 }
 
+static int ksz9031_center_flp_timing(struct phy_device *phydev)
+{
+	int result;
+
+	/* Center KSZ9031RNX FLP timing at 16ms. */
+	result = ksz9031_extended_write(phydev, OP_DATA, 0,
+					MII_KSZ9031RN_FLP_BURST_TX_HI, 0x0006);
+	result = ksz9031_extended_write(phydev, OP_DATA, 0,
+					MII_KSZ9031RN_FLP_BURST_TX_LO, 0x1A80);
+
+	if (result)
+		return result;
+
+	return genphy_restart_aneg(phydev);
+}
+
 static int ksz9031_config_init(struct phy_device *phydev)
 {
 	const struct device *dev = &phydev->dev;
@@ -462,7 +482,8 @@ static int ksz9031_config_init(struct phy_device *phydev)
 				MII_KSZ9031RN_TX_DATA_PAD_SKEW, 4,
 				tx_data_skews, 4);
 	}
-	return 0;
+
+	return ksz9031_center_flp_timing(phydev);
 }
 
 #define KSZ8873MLL_GLOBAL_CONTROL_4	0x06
-- 
2.1.4

Re: [PATCH v3 3/3] net/phy: micrel: Center FLP timing at 16ms

[Florian Fainelli]

On 05/06/15 15:40, Jaeden Amero wrote:
> Link failures have been observed when using the KSZ9031 with HP 1810-8G
> and HP 1910-8G network switches. Center the FLP timing at 16ms to help
> avoid intermittent link failures.
> 
> From the KSZ9031RNX and KSZ9031MNX data sheets revision 2.2, section
> "Auto-Negotiation Timing":
> 	The KSZ9031[RNX or MNX] Fast Link Pulse (FLP) burst-to-burst
> 	transmit timing for Auto-Negotiation defaults to 8ms. IEEE 802.3
> 	Standard specifies this timing to be 16ms +/-8ms. Some PHY link
> 	partners need to receive the FLP with 16ms centered timing;
> 	otherwise, there can be intermittent link failures and long
> 	link-up times.
> 
> 	After KSZ9031[RNX or MNX] power-up/reset, program the following
> 	register sequence to set the FLP timing to 16ms
> 
> 	Write Register Dh = 0x0000 // Set up register address for MMD – Device Address 0h
> 	Write Register Eh = 0x0004 // Select Register 4h of MMD – Device Address 0h
> 	Write Register Dh = 0x4000 // Select register data for MMD – Device Address 0h, Register 4h
> 	Write Register Eh = 0x0006 // Write value 0x0006 to MMD – Device Address 0h, Register 4h
> 	Write Register Dh = 0x0000 // Set up register address for MMD – Device Address 0h
> 	Write Register Eh = 0x0003 // Select Register 3h of MMD – Device Address 0h
> 	Write Register Dh = 0x4000 // Select register data for MMD – Device Address 0h, Register 3h
> 	Write Register Eh = 0x1A80 // Write value 0x1A80 to MMD – Device Address 0h, Register 3h
> 	Write Register 0h, Bit [9] = 1 // Restart Auto-Negotiation

Quoting a portion of the data-sheet on how to do this programming is
very strange considering that the code is going to be the reference, not
the commit message.

Other than that, this looks reasonable.

> 
> Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
> ---
>  drivers/net/phy/micrel.c | 23 ++++++++++++++++++++++-
>  1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index f23765e..499185e 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -366,6 +366,10 @@ static int ksz9021_config_init(struct phy_device *phydev)
>  #define KSZ9031_PS_TO_REG		60
>  
>  /* Extended registers */
> +/* MMD Address 0x0 */
> +#define MII_KSZ9031RN_FLP_BURST_TX_LO	3
> +#define MII_KSZ9031RN_FLP_BURST_TX_HI	4
> +
>  /* MMD Address 0x2 */
>  #define MII_KSZ9031RN_CONTROL_PAD_SKEW	4
>  #define MII_KSZ9031RN_RX_DATA_PAD_SKEW	5
> @@ -427,6 +431,22 @@ static int ksz9031_of_load_skew_values(struct phy_device *phydev,
>  	return ksz9031_extended_write(phydev, OP_DATA, 2, reg, newval);
>  }
>  
> +static int ksz9031_center_flp_timing(struct phy_device *phydev)
> +{
> +	int result;
> +
> +	/* Center KSZ9031RNX FLP timing at 16ms. */
> +	result = ksz9031_extended_write(phydev, OP_DATA, 0,
> +					MII_KSZ9031RN_FLP_BURST_TX_HI, 0x0006);
> +	result = ksz9031_extended_write(phydev, OP_DATA, 0,
> +					MII_KSZ9031RN_FLP_BURST_TX_LO, 0x1A80);
> +
> +	if (result)
> +		return result;
> +
> +	return genphy_restart_aneg(phydev);
> +}
> +
>  static int ksz9031_config_init(struct phy_device *phydev)
>  {
>  	const struct device *dev = &phydev->dev;
> @@ -462,7 +482,8 @@ static int ksz9031_config_init(struct phy_device *phydev)
>  				MII_KSZ9031RN_TX_DATA_PAD_SKEW, 4,
>  				tx_data_skews, 4);
>  	}
> -	return 0;
> +
> +	return ksz9031_center_flp_timing(phydev);
>  }
>  
>  #define KSZ8873MLL_GLOBAL_CONTROL_4	0x06
> 


-- 
Florian

Re: [PATCH v3 0/3] net/phy: micrel: Center FLP timing at 16ms

[Florian Fainelli]

On 05/06/15 15:40, Jaeden Amero wrote:
> In v2, we add an additional cleanup commit to make an array of strings
> static const and to improve const correctness generally. We also no longer
> unnecessarily initialize the result variable in
> ksz9031_center_flp_timing().
> 
> In v3, we remove the unnecessary result variable from ksz9031_config_init()
> introduced by a previous version of "net/phy: micrel: Center FLP timing at
> 16ms".

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

> 
> Jaeden Amero (3):
>   net/phy: micrel: Be more const correct
>   net/phy: micrel: Comment MMD address of extended registers
>   net/phy: micrel: Center FLP timing at 16ms
> 
>  drivers/net/phy/micrel.c | 53 ++++++++++++++++++++++++++++++++++--------------
>  1 file changed, 38 insertions(+), 15 deletions(-)
> 


-- 
Florian

Re: [PATCH v3 3/3] net/phy: micrel: Center FLP timing at 16ms

[Jaeden Amero]

On 06/05/2015 05:43 PM, Florian Fainelli wrote:
> On 05/06/15 15:40, Jaeden Amero wrote:
>> Link failures have been observed when using the KSZ9031 with HP 1810-8G
>> and HP 1910-8G network switches. Center the FLP timing at 16ms to help
>> avoid intermittent link failures.
>>
>> From the KSZ9031RNX and KSZ9031MNX data sheets revision 2.2, section
>> "Auto-Negotiation Timing":
>> 	The KSZ9031[RNX or MNX] Fast Link Pulse (FLP) burst-to-burst
>> 	transmit timing for Auto-Negotiation defaults to 8ms. IEEE 802.3
>> 	Standard specifies this timing to be 16ms +/-8ms. Some PHY link
>> 	partners need to receive the FLP with 16ms centered timing;
>> 	otherwise, there can be intermittent link failures and long
>> 	link-up times.
>>
>> 	After KSZ9031[RNX or MNX] power-up/reset, program the following
>> 	register sequence to set the FLP timing to 16ms
>>
>> 	Write Register Dh = 0x0000 // Set up register address for MMD – Device Address 0h
>> 	Write Register Eh = 0x0004 // Select Register 4h of MMD – Device Address 0h
>> 	Write Register Dh = 0x4000 // Select register data for MMD – Device Address 0h, Register 4h
>> 	Write Register Eh = 0x0006 // Write value 0x0006 to MMD – Device Address 0h, Register 4h
>> 	Write Register Dh = 0x0000 // Set up register address for MMD – Device Address 0h
>> 	Write Register Eh = 0x0003 // Select Register 3h of MMD – Device Address 0h
>> 	Write Register Dh = 0x4000 // Select register data for MMD – Device Address 0h, Register 3h
>> 	Write Register Eh = 0x1A80 // Write value 0x1A80 to MMD – Device Address 0h, Register 3h
>> 	Write Register 0h, Bit [9] = 1 // Restart Auto-Negotiation
> 
> Quoting a portion of the data-sheet on how to do this programming is
> very strange considering that the code is going to be the reference, not
> the commit message.

I included it for lack of something better to quote that explained
which values to set when. I'd be happy to revise the message as this
appears too strange.

> Other than that, this looks reasonable.

Thanks very much for the review.

Cheers,
Jaeden