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| author | Jaeden Amero <jaeden.amero@ni.com> | 2015-06-05 18:00:26 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-06-08 00:50:48 -0700 |
| commit | 6270e1ae804ae781cdd3cc20eadfa4b6fb090ab7 (patch) | |
| tree | 6dfa367a0bf5fb7688fbe57d8e633d3cbff0a814 /drivers | |
| parent | ae6c97bb096df970c8e8095fcc84143a01fa02f2 (diff) | |
| download | linux-6270e1ae804ae781cdd3cc20eadfa4b6fb090ab7.tar.bz2 | |
net/phy: micrel: Center FLP timing at 16ms
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/phy/micrel.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c index f23765ea6f65..499185eaf413 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 |