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net/phy: micrel: Center FLP timing at 16ms

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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>
This commit is contained in:
Jaeden Amero 2015-06-05 18:00:26 -05:00 committed by David S. Miller
parent ae6c97bb09
commit 6270e1ae80
1 changed files with 22 additions and 1 deletions
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23
drivers/net/phy/micrel.c
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@ -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