From: Corinna Vinschen <vinschen@xxxxxxxxxx>
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@xxxxxxxxx>
Co-developed-by: Jamie Bainbridge <jbainbri@xxxxxxxxxx>
Signed-off-by: Jamie Bainbridge <jbainbri@xxxxxxxxxx>
Signed-off-by: Corinna Vinschen <vinschen@xxxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230214185549.1306522-1-anthony.l.nguyen@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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");
--
2.39.1
