From: Corinna Vinschen vinschen@redhat.com
commit 5d54cb1767e06025819daa6769e0f18dcbc60936 upstream.
Commit a97f8783a937 ("igb: unbreak I2C bit-banging on i350") introduced code to change I2C settings to bit banging unconditionally.
However, this patch introduced a regression: On an Intel S2600CWR Server Board with three NICs:
- 1x dual-port copper Intel I350 Gigabit Network Connection [8086:1521] (rev 01) fw 1.63, 0x80000dda
- 2x quad-port SFP+ with copper SFP Avago ABCU-5700RZ Intel I350 Gigabit Fiber Network Connection [8086:1522] (rev 01) fw 1.52.0
the SFP NICs no longer get link at all. Reverting commit a97f8783a937 or switching to the Intel out-of-tree driver both fix the problem.
Per the igb out-of-tree driver, I2C bit banging on i350 depends on support for an external thermal sensor (ETS). However, commit a97f8783a937 added bit banging unconditionally. Additionally, the out-of-tree driver always calls init_thermal_sensor_thresh on probe, while our driver only calls init_thermal_sensor_thresh only in igb_reset(), and only if an ETS is present, ignoring the internal thermal sensor. The affected SFPs don't provide an ETS. Per Intel, the behaviour is a result of i350 firmware requirements.
This patch fixes the problem by aligning the behaviour to the out-of-tree driver:
- split igb_init_i2c() into two functions: - igb_init_i2c() only performs the basic I2C initialization. - igb_set_i2c_bb() makes sure that E1000_CTRL_I2C_ENA is set and enables bit-banging.
- igb_probe() only calls igb_set_i2c_bb() if an ETS is present.
- igb_probe() calls init_thermal_sensor_thresh() unconditionally.
- igb_reset() aligns its behaviour to igb_probe(), i. e., call igb_set_i2c_bb() if an ETS is present and call init_thermal_sensor_thresh() unconditionally.
Fixes: a97f8783a937 ("igb: unbreak I2C bit-banging on i350") Tested-by: Mateusz Palczewski mateusz.palczewski@intel.com Co-developed-by: Jamie Bainbridge jbainbri@redhat.com Signed-off-by: Jamie Bainbridge jbainbri@redhat.com Signed-off-by: Corinna Vinschen vinschen@redhat.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Link: https://lore.kernel.org/r/20230214185549.1306522-1-anthony.l.nguyen@intel.co... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/intel/igb/igb_main.c | 42 +++++++++++++++++------ 1 file changed, 32 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index d8e3048b93dd..b5b443883da9 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -2256,6 +2256,30 @@ static void igb_enable_mas(struct igb_adapter *adapter) } }
+#ifdef CONFIG_IGB_HWMON +/** + * igb_set_i2c_bb - Init I2C interface + * @hw: pointer to hardware structure + **/ +static void igb_set_i2c_bb(struct e1000_hw *hw) +{ + u32 ctrl_ext; + s32 i2cctl; + + ctrl_ext = rd32(E1000_CTRL_EXT); + ctrl_ext |= E1000_CTRL_I2C_ENA; + wr32(E1000_CTRL_EXT, ctrl_ext); + wrfl(); + + i2cctl = rd32(E1000_I2CPARAMS); + i2cctl |= E1000_I2CBB_EN + | E1000_I2C_CLK_OE_N + | E1000_I2C_DATA_OE_N; + wr32(E1000_I2CPARAMS, i2cctl); + wrfl(); +} +#endif + void igb_reset(struct igb_adapter *adapter) { struct pci_dev *pdev = adapter->pdev; @@ -2400,7 +2424,8 @@ void igb_reset(struct igb_adapter *adapter) * interface. */ if (adapter->ets) - mac->ops.init_thermal_sensor_thresh(hw); + igb_set_i2c_bb(hw); + mac->ops.init_thermal_sensor_thresh(hw); } } #endif @@ -3117,21 +3142,12 @@ static void igb_init_mas(struct igb_adapter *adapter) **/ static s32 igb_init_i2c(struct igb_adapter *adapter) { - struct e1000_hw *hw = &adapter->hw; s32 status = 0; - s32 i2cctl;
/* I2C interface supported on i350 devices */ if (adapter->hw.mac.type != e1000_i350) return 0;
- i2cctl = rd32(E1000_I2CPARAMS); - i2cctl |= E1000_I2CBB_EN - | E1000_I2C_CLK_OUT | E1000_I2C_CLK_OE_N - | E1000_I2C_DATA_OUT | E1000_I2C_DATA_OE_N; - wr32(E1000_I2CPARAMS, i2cctl); - wrfl(); - /* Initialize the i2c bus which is controlled by the registers. * This bus will use the i2c_algo_bit structure that implements * the protocol through toggling of the 4 bits in the register. @@ -3521,6 +3537,12 @@ static int igb_probe(struct pci_dev *pdev, const struct pci_device_id *ent) adapter->ets = true; else adapter->ets = false; + /* Only enable I2C bit banging if an external thermal + * sensor is supported. + */ + if (adapter->ets) + igb_set_i2c_bb(hw); + hw->mac.ops.init_thermal_sensor_thresh(hw); if (igb_sysfs_init(adapter)) dev_err(&pdev->dev, "failed to allocate sysfs resources\n");