| From a1832074a95013aa02705f8889245f6762da5a45 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 1 Nov 2021 18:39:36 -0700 |
| Subject: ixgbe: set X550 MDIO speed before talking to PHY |
| |
| From: Cyril Novikov <cnovikov@lynx.com> |
| |
| [ Upstream commit bf0a375055bd1afbbf02a0ef45f7655da7b71317 ] |
| |
| The MDIO bus speed must be initialized before talking to the PHY the first |
| time in order to avoid talking to it using a speed that the PHY doesn't |
| support. |
| |
| This fixes HW initialization error -17 (IXGBE_ERR_PHY_ADDR_INVALID) on |
| Denverton CPUs (a.k.a. the Atom C3000 family) on ports with a 10Gb network |
| plugged in. On those devices, HLREG0[MDCSPD] resets to 1, which combined |
| with the 10Gb network results in a 24MHz MDIO speed, which is apparently |
| too fast for the connected PHY. PHY register reads over MDIO bus return |
| garbage, leading to initialization failure. |
| |
| Reproduced with Linux kernel 4.19 and 5.15-rc7. Can be reproduced using |
| the following setup: |
| |
| * Use an Atom C3000 family system with at least one X552 LAN on the SoC |
| * Disable PXE or other BIOS network initialization if possible |
| (the interface must not be initialized before Linux boots) |
| * Connect a live 10Gb Ethernet cable to an X550 port |
| * Power cycle (not reset, doesn't always work) the system and boot Linux |
| * Observe: ixgbe interfaces w/ 10GbE cables plugged in fail with error -17 |
| |
| Fixes: e84db7272798 ("ixgbe: Introduce function to control MDIO speed") |
| Signed-off-by: Cyril Novikov <cnovikov@lynx.com> |
| Reviewed-by: Andrew Lunn <andrew@lunn.ch> |
| Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c |
| index 9724ffb165189..e4b50c7781ffa 100644 |
| --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c |
| +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c |
| @@ -3405,6 +3405,9 @@ static s32 ixgbe_reset_hw_X550em(struct ixgbe_hw *hw) |
| /* flush pending Tx transactions */ |
| ixgbe_clear_tx_pending(hw); |
| |
| + /* set MDIO speed before talking to the PHY in case it's the 1st time */ |
| + ixgbe_set_mdio_speed(hw); |
| + |
| /* PHY ops must be identified and initialized prior to reset */ |
| status = hw->phy.ops.init(hw); |
| if (status == IXGBE_ERR_SFP_NOT_SUPPORTED || |
| -- |
| 2.33.0 |
| |