[PATCH v2 3/3] net/phy: micrel: Center FLP timing at 16ms

2015-06-05 Thread 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 = 0x // 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 = 0x // 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.am...@ni.com
---
 drivers/net/phy/micrel.c | 26 +-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index f23765e..e156e36 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;
@@ -441,6 +461,7 @@ static int ksz9031_config_init(struct phy_device *phydev)
txd2-skew-ps, txd3-skew-ps
};
static const char *control_skews[2] = {txen-skew-ps, rxdv-skew-ps};
+   int result;
 
if (!of_node  dev-parent-of_node)
of_node = dev-parent-of_node;
@@ -462,7 +483,10 @@ static int ksz9031_config_init(struct phy_device *phydev)
MII_KSZ9031RN_TX_DATA_PAD_SKEW, 4,
tx_data_skews, 4);
}
-   return 0;
+
+   result = ksz9031_center_flp_timing(phydev);
+
+   return result;
 }
 
 #define KSZ8873MLL_GLOBAL_CONTROL_40x06
-- 
2.1.4

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Re: [PATCH v2 3/3] net/phy: micrel: Center FLP timing at 16ms

2015-06-05 Thread Sergei Shtylyov 

Hello.

On 06/05/2015 10:55 PM, 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 = 0x // 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 = 0x // 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.am...@ni.com
---
  drivers/net/phy/micrel.c | 26 +-
  1 file changed, 25 insertions(+), 1 deletion(-)



diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index f23765e..e156e36 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c

[...]

@@ -441,6 +461,7 @@ static int ksz9031_config_init(struct phy_device *phydev)
txd2-skew-ps, txd3-skew-ps
};
static const char *control_skews[2] = {txen-skew-ps, rxdv-skew-ps};
+   int result;


   You hardly need this variable...



if (!of_node  dev-parent-of_node)
of_node = dev-parent-of_node;
@@ -462,7 +483,10 @@ static int ksz9031_config_init(struct phy_device *phydev)
MII_KSZ9031RN_TX_DATA_PAD_SKEW, 4,
tx_data_skews, 4);
}
-   return 0;
+
+   result = ksz9031_center_flp_timing(phydev);
+
+   return result;


   Why not just return directly?

[...]

WBR, Sergei

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Re: [PATCH v2 3/3] net/phy: micrel: Center FLP timing at 16ms

2015-06-05 Thread Jaeden Amero 
On 06/05/2015 04:09 PM, Sergei Shtylyov wrote:
 @@ -441,6 +461,7 @@ static int ksz9031_config_init(struct phy_device
 *phydev)
   txd2-skew-ps, txd3-skew-ps
   };
   static const char *control_skews[2] = {txen-skew-ps,
 rxdv-skew-ps};
 +int result;
 
You hardly need this variable...
 

   if (!of_node  dev-parent-of_node)
   of_node = dev-parent-of_node;
 @@ -462,7 +483,10 @@ static int ksz9031_config_init(struct phy_device
 *phydev)
   MII_KSZ9031RN_TX_DATA_PAD_SKEW, 4,
   tx_data_skews, 4);
   }
 -return 0;
 +
 +result = ksz9031_center_flp_timing(phydev);
 +
 +return result;
 
Why not just return directly?
 

Genius.

Thanks for the feedback. I'll post a v3.
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