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e1000e: Workaround for sporadic MDI error on Meteor Lake systems
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On some Meteor Lake systems accessing the PHY via the MDIO interface may
result in an MDI error. This issue happens sporadically and in most cases
a second access to the PHY via the MDIO interface results in success.

As a workaround, introduce a retry counter which is set to 3 on Meteor
Lake systems. The driver will only return an error if 3 consecutive PHY
access attempts fail. The retry mechanism is disabled in specific flows,
where MDI errors are expected.

Fixes: cc23f4f ("e1000e: Add support for Meteor Lake")
Suggested-by: Nikolay Mushayev <nikolay.mushayev@intel.com>
Co-developed-by: Nir Efrati <nir.efrati@intel.com>
Signed-off-by: Nir Efrati <nir.efrati@intel.com>
Signed-off-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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@vlifshts @anguy11
vlifshts authored and anguy11 committed Mar 27, 2024
1 parent afbf75e commit 6dbdd4d
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Showing 4 changed files with 150 additions and 69 deletions.
2 changes: 2 additions & 0 deletions drivers/net/ethernet/intel/e1000e/hw.h
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Original file line number Diff line number Diff line change
Expand Up @@ -628,6 +628,7 @@ struct e1000_phy_info {
u32 id;
u32 reset_delay_us; /* in usec */
u32 revision;
u32 retry_count;

enum e1000_media_type media_type;

Expand All @@ -644,6 +645,7 @@ struct e1000_phy_info {
bool polarity_correction;
bool speed_downgraded;
bool autoneg_wait_to_complete;
bool retry_enabled;
};

struct e1000_nvm_info {
Expand Down
33 changes: 33 additions & 0 deletions drivers/net/ethernet/intel/e1000e/ich8lan.c
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Original file line number Diff line number Diff line change
Expand Up @@ -222,11 +222,18 @@ static bool e1000_phy_is_accessible_pchlan(struct e1000_hw *hw)
if (hw->mac.type >= e1000_pch_lpt) {
/* Only unforce SMBus if ME is not active */
if (!(er32(FWSM) & E1000_ICH_FWSM_FW_VALID)) {
/* Switching PHY interface always returns MDI error
* so disable retry mechanism to avoid wasting time
*/
e1000e_disable_phy_retry(hw);

/* Unforce SMBus mode in PHY */
e1e_rphy_locked(hw, CV_SMB_CTRL, &phy_reg);
phy_reg &= ~CV_SMB_CTRL_FORCE_SMBUS;
e1e_wphy_locked(hw, CV_SMB_CTRL, phy_reg);

e1000e_enable_phy_retry(hw);

/* Unforce SMBus mode in MAC */
mac_reg = er32(CTRL_EXT);
mac_reg &= ~E1000_CTRL_EXT_FORCE_SMBUS;
Expand Down Expand Up @@ -310,6 +317,11 @@ static s32 e1000_init_phy_workarounds_pchlan(struct e1000_hw *hw)
goto out;
}

/* There is no guarantee that the PHY is accessible at this time
* so disable retry mechanism to avoid wasting time
*/
e1000e_disable_phy_retry(hw);

/* The MAC-PHY interconnect may be in SMBus mode. If the PHY is
* inaccessible and resetting the PHY is not blocked, toggle the
* LANPHYPC Value bit to force the interconnect to PCIe mode.
Expand Down Expand Up @@ -380,6 +392,8 @@ static s32 e1000_init_phy_workarounds_pchlan(struct e1000_hw *hw)
break;
}

e1000e_enable_phy_retry(hw);

hw->phy.ops.release(hw);
if (!ret_val) {

Expand Down Expand Up @@ -449,6 +463,11 @@ static s32 e1000_init_phy_params_pchlan(struct e1000_hw *hw)

phy->id = e1000_phy_unknown;

if (hw->mac.type == e1000_pch_mtp) {
phy->retry_count = 2;
e1000e_enable_phy_retry(hw);
}

ret_val = e1000_init_phy_workarounds_pchlan(hw);
if (ret_val)
return ret_val;
Expand Down Expand Up @@ -1146,13 +1165,20 @@ s32 e1000_enable_ulp_lpt_lp(struct e1000_hw *hw, bool to_sx)
if (ret_val)
goto out;

/* Switching PHY interface always returns MDI error
* so disable retry mechanism to avoid wasting time
*/
e1000e_disable_phy_retry(hw);

/* Force SMBus mode in PHY */
ret_val = e1000_read_phy_reg_hv_locked(hw, CV_SMB_CTRL, &phy_reg);
if (ret_val)
goto release;
phy_reg |= CV_SMB_CTRL_FORCE_SMBUS;
e1000_write_phy_reg_hv_locked(hw, CV_SMB_CTRL, phy_reg);

e1000e_enable_phy_retry(hw);

/* Force SMBus mode in MAC */
mac_reg = er32(CTRL_EXT);
mac_reg |= E1000_CTRL_EXT_FORCE_SMBUS;
Expand Down Expand Up @@ -1313,6 +1339,11 @@ static s32 e1000_disable_ulp_lpt_lp(struct e1000_hw *hw, bool force)
/* Toggle LANPHYPC Value bit */
e1000_toggle_lanphypc_pch_lpt(hw);

/* Switching PHY interface always returns MDI error
* so disable retry mechanism to avoid wasting time
*/
e1000e_disable_phy_retry(hw);

/* Unforce SMBus mode in PHY */
ret_val = e1000_read_phy_reg_hv_locked(hw, CV_SMB_CTRL, &phy_reg);
if (ret_val) {
Expand All @@ -1333,6 +1364,8 @@ static s32 e1000_disable_ulp_lpt_lp(struct e1000_hw *hw, bool force)
phy_reg &= ~CV_SMB_CTRL_FORCE_SMBUS;
e1000_write_phy_reg_hv_locked(hw, CV_SMB_CTRL, phy_reg);

e1000e_enable_phy_retry(hw);

/* Unforce SMBus mode in MAC */
mac_reg = er32(CTRL_EXT);
mac_reg &= ~E1000_CTRL_EXT_FORCE_SMBUS;
Expand Down
182 changes: 113 additions & 69 deletions drivers/net/ethernet/intel/e1000e/phy.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -107,6 +107,16 @@ s32 e1000e_phy_reset_dsp(struct e1000_hw *hw)
return e1e_wphy(hw, M88E1000_PHY_GEN_CONTROL, 0);
}

void e1000e_disable_phy_retry(struct e1000_hw *hw)
{
hw->phy.retry_enabled = false;
}

void e1000e_enable_phy_retry(struct e1000_hw *hw)
{
hw->phy.retry_enabled = true;
}

/**
* e1000e_read_phy_reg_mdic - Read MDI control register
* @hw: pointer to the HW structure
Expand All @@ -118,55 +128,73 @@ s32 e1000e_phy_reset_dsp(struct e1000_hw *hw)
**/
s32 e1000e_read_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 *data)
{
u32 i, mdic = 0, retry_counter, retry_max;
struct e1000_phy_info *phy = &hw->phy;
u32 i, mdic = 0;
bool success;

if (offset > MAX_PHY_REG_ADDRESS) {
e_dbg("PHY Address %d is out of range\n", offset);
return -E1000_ERR_PARAM;
}

retry_max = phy->retry_enabled ? phy->retry_count : 0;

/* Set up Op-code, Phy Address, and register offset in the MDI
* Control register. The MAC will take care of interfacing with the
* PHY to retrieve the desired data.
*/
mdic = ((offset << E1000_MDIC_REG_SHIFT) |
(phy->addr << E1000_MDIC_PHY_SHIFT) |
(E1000_MDIC_OP_READ));
for (retry_counter = 0; retry_counter <= retry_max; retry_counter++) {
success = true;

ew32(MDIC, mdic);
mdic = ((offset << E1000_MDIC_REG_SHIFT) |
(phy->addr << E1000_MDIC_PHY_SHIFT) |
(E1000_MDIC_OP_READ));

/* Poll the ready bit to see if the MDI read completed
* Increasing the time out as testing showed failures with
* the lower time out
*/
for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 3); i++) {
udelay(50);
mdic = er32(MDIC);
if (mdic & E1000_MDIC_READY)
break;
}
if (!(mdic & E1000_MDIC_READY)) {
e_dbg("MDI Read PHY Reg Address %d did not complete\n", offset);
return -E1000_ERR_PHY;
}
if (mdic & E1000_MDIC_ERROR) {
e_dbg("MDI Read PHY Reg Address %d Error\n", offset);
return -E1000_ERR_PHY;
}
if (FIELD_GET(E1000_MDIC_REG_MASK, mdic) != offset) {
e_dbg("MDI Read offset error - requested %d, returned %d\n",
offset, FIELD_GET(E1000_MDIC_REG_MASK, mdic));
return -E1000_ERR_PHY;
ew32(MDIC, mdic);

/* Poll the ready bit to see if the MDI read completed
* Increasing the time out as testing showed failures with
* the lower time out
*/
for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 3); i++) {
usleep_range(50, 60);
mdic = er32(MDIC);
if (mdic & E1000_MDIC_READY)
break;
}
if (!(mdic & E1000_MDIC_READY)) {
e_dbg("MDI Read PHY Reg Address %d did not complete\n",
offset);
success = false;
}
if (mdic & E1000_MDIC_ERROR) {
e_dbg("MDI Read PHY Reg Address %d Error\n", offset);
success = false;
}
if (FIELD_GET(E1000_MDIC_REG_MASK, mdic) != offset) {
e_dbg("MDI Read offset error - requested %d, returned %d\n",
offset, FIELD_GET(E1000_MDIC_REG_MASK, mdic));
success = false;
}

/* Allow some time after each MDIC transaction to avoid
* reading duplicate data in the next MDIC transaction.
*/
if (hw->mac.type == e1000_pch2lan)
usleep_range(100, 150);

if (success) {
*data = (u16)mdic;
return 0;
}

if (retry_counter != retry_max) {
e_dbg("Perform retry on PHY transaction...\n");
mdelay(10);
}
}
*data = (u16)mdic;

/* Allow some time after each MDIC transaction to avoid
* reading duplicate data in the next MDIC transaction.
*/
if (hw->mac.type == e1000_pch2lan)
udelay(100);
return 0;
return -E1000_ERR_PHY;
}

/**
Expand All @@ -179,56 +207,72 @@ s32 e1000e_read_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 *data)
**/
s32 e1000e_write_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 data)
{
u32 i, mdic = 0, retry_counter, retry_max;
struct e1000_phy_info *phy = &hw->phy;
u32 i, mdic = 0;
bool success;

if (offset > MAX_PHY_REG_ADDRESS) {
e_dbg("PHY Address %d is out of range\n", offset);
return -E1000_ERR_PARAM;
}

retry_max = phy->retry_enabled ? phy->retry_count : 0;

/* Set up Op-code, Phy Address, and register offset in the MDI
* Control register. The MAC will take care of interfacing with the
* PHY to retrieve the desired data.
*/
mdic = (((u32)data) |
(offset << E1000_MDIC_REG_SHIFT) |
(phy->addr << E1000_MDIC_PHY_SHIFT) |
(E1000_MDIC_OP_WRITE));
for (retry_counter = 0; retry_counter <= retry_max; retry_counter++) {
success = true;

ew32(MDIC, mdic);
mdic = (((u32)data) |
(offset << E1000_MDIC_REG_SHIFT) |
(phy->addr << E1000_MDIC_PHY_SHIFT) |
(E1000_MDIC_OP_WRITE));

/* Poll the ready bit to see if the MDI read completed
* Increasing the time out as testing showed failures with
* the lower time out
*/
for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 3); i++) {
udelay(50);
mdic = er32(MDIC);
if (mdic & E1000_MDIC_READY)
break;
}
if (!(mdic & E1000_MDIC_READY)) {
e_dbg("MDI Write PHY Reg Address %d did not complete\n", offset);
return -E1000_ERR_PHY;
}
if (mdic & E1000_MDIC_ERROR) {
e_dbg("MDI Write PHY Red Address %d Error\n", offset);
return -E1000_ERR_PHY;
}
if (FIELD_GET(E1000_MDIC_REG_MASK, mdic) != offset) {
e_dbg("MDI Write offset error - requested %d, returned %d\n",
offset, FIELD_GET(E1000_MDIC_REG_MASK, mdic));
return -E1000_ERR_PHY;
}
ew32(MDIC, mdic);

/* Allow some time after each MDIC transaction to avoid
* reading duplicate data in the next MDIC transaction.
*/
if (hw->mac.type == e1000_pch2lan)
udelay(100);
/* Poll the ready bit to see if the MDI read completed
* Increasing the time out as testing showed failures with
* the lower time out
*/
for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 3); i++) {
usleep_range(50, 60);
mdic = er32(MDIC);
if (mdic & E1000_MDIC_READY)
break;
}
if (!(mdic & E1000_MDIC_READY)) {
e_dbg("MDI Write PHY Reg Address %d did not complete\n",
offset);
success = false;
}
if (mdic & E1000_MDIC_ERROR) {
e_dbg("MDI Write PHY Reg Address %d Error\n", offset);
success = false;
}
if (FIELD_GET(E1000_MDIC_REG_MASK, mdic) != offset) {
e_dbg("MDI Write offset error - requested %d, returned %d\n",
offset, FIELD_GET(E1000_MDIC_REG_MASK, mdic));
success = false;
}

return 0;
/* Allow some time after each MDIC transaction to avoid
* reading duplicate data in the next MDIC transaction.
*/
if (hw->mac.type == e1000_pch2lan)
usleep_range(100, 150);

if (success)
return 0;

if (retry_counter != retry_max) {
e_dbg("Perform retry on PHY transaction...\n");
mdelay(10);
}
}

return -E1000_ERR_PHY;
}

/**
Expand Down
2 changes: 2 additions & 0 deletions drivers/net/ethernet/intel/e1000e/phy.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,8 @@ s32 e1000e_read_phy_reg_bm2(struct e1000_hw *hw, u32 offset, u16 *data);
s32 e1000e_write_phy_reg_bm2(struct e1000_hw *hw, u32 offset, u16 data);
void e1000_power_up_phy_copper(struct e1000_hw *hw);
void e1000_power_down_phy_copper(struct e1000_hw *hw);
void e1000e_disable_phy_retry(struct e1000_hw *hw);
void e1000e_enable_phy_retry(struct e1000_hw *hw);
s32 e1000e_read_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 *data);
s32 e1000e_write_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 data);
s32 e1000_read_phy_reg_hv(struct e1000_hw *hw, u32 offset, u16 *data);
Expand Down

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