net/phy: micrel: Center FLP timing at 16ms (6270e1ae) · Commits · 戴 / test

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>

drivers/net/phy/micrel.c

+22 −1

Original line number	Diff line number	Diff line
		@@ -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

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