[PATCH v4 0/3] net/phy: micrel: Center FLP timing at 16ms

[PATCH v4 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".

In v4, we modify the commit message of "net/phy: micrel: Center FLP timing
at 16ms" to replace the awkward quotation of the data sheet's programming
procedure with an explanation of why we program the FLP burst registers and
restart auto-negotiation where we do (config_init).

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 v4 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 v4 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 v4 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.

The PHY data sheet recommends configuring the FLP burst registers after
power-up/reset and immediately thereafter restarting auto-negotiation, so
we center the FLP timing at 16ms and then restart auto-negotiation in the
config_init for KSZ9031.

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 v4 0/3] net/phy: micrel: Center FLP timing at 16ms

[David Miller]

From: Jaeden Amero <jaeden.amero@ni.com>
Date: Fri, 5 Jun 2015 18:00:23 -0500

> 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".
> 
> In v4, we modify the commit message of "net/phy: micrel: Center FLP timing
> at 16ms" to replace the awkward quotation of the data sheet's programming
> procedure with an explanation of why we program the FLP burst registers and
> restart auto-negotiation where we do (config_init).

Series applied to net-next, thanks.