RE: [Intel-wired-lan] [PATCH iwl-net v3] ice: fall back to SBQ when LL PHY timer interface times out

-----Original Message-----
From: Intel-wired-lan <redacted> On Behalf
Of Przemyslaw Korba
Sent: Friday, June 5, 2026 2:06 PM
To: intel-wired-lan@lists.osuosl.org
Cc: netdev@vger.kernel.org; Nguyen, Anthony L
[off-list ref]; Kitszel, Przemyslaw
[off-list ref]; Ilichev, Konstantin
[off-list ref]; Lobakin, Aleksander
[off-list ref]; Korba, Przemyslaw
[off-list ref]
Subject: [Intel-wired-lan] [PATCH iwl-net v3] ice: fall back to SBQ
when LL PHY timer interface times out

The low-latency (LL) PHY timer interface relies on a tight, atomic
poll of the PF_SB_ATQBAL register with a 2ms timeout. After an NVM
update / EMPR, FW may need significantly longer than 2ms to start
responding to ATQBAL commands. The first PHY adjust or incval write
issued by
ice_ptp_rebuild_owner() fails with -ETIMEDOUT.

Fix this by falling back to the existing SBQ-based PHY register write
path when LL times out. This makes sure PTP is initialized when FW
takes longer than expected to come back online.

Steps to reproduce:
./nvmupdate64e -if devlink -f
Update E810 card with nvmupdate64e, and observe dmesg errors:
  Failed to write PHC increment value, status -110
  PTP reset failed, error: -110 (-ETIMEDOUT)

Fixes: ef9a64c07294 ("ice: implement low latency PHY timer updates")
Signed-off-by: Przemyslaw Korba <redacted>
---
v3:
* actually add TIMEDOUT check in ice_prep_phy_adj_e810 (did do it)
v2:
* add TIMEDOUT check in ice_prep_phy_adj_e810 (did not do it)
https://lore.kernel.org/intel-wired-lan/20260603114904.1297713-1-
przemyslaw.korba@intel.com/
v1:
https://lore.kernel.org/intel-wired-lan/20260511095830.1095984-1-
przemyslaw.korba@intel.com/
---
 drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 38 +++++++++++---------
-
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c

b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
index d47d5baf3281..e77c7f2b5575 100644

--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c

@@ -4789,15 +4789,12 @@ static int ice_ptp_prep_phy_adj_ll_e810(struct

ice_hw *hw, s32 adj)
 				       !FIELD_GET(REG_LL_PROXY_H_EXEC,
val),
 				       10, REG_LL_PROXY_H_TIMEOUT_US,
false, hw,
 				       REG_LL_PROXY_H);
-	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to prepare PHY timer
adjustment using low latency interface\n");
-		spin_unlock_irq(&params->atqbal_wq.lock);
-		return err;
-	}
-
 	spin_unlock_irq(&params->atqbal_wq.lock);

-	return 0;
+	if (err)
+		ice_debug(hw, ICE_DBG_PTP, "Failed to prepare PHY timer
adjustment
+using low latency interface\n");
+
+	return err;
 }

 /**

@@ -4818,8 +4815,12 @@ static int ice_ptp_prep_phy_adj_e810(struct

ice_hw *hw, s32 adj)
 	u8 tmr_idx;
 	int err;

-	if (hw->dev_caps.ts_dev_info.ll_phy_tmr_update)
-		return ice_ptp_prep_phy_adj_ll_e810(hw, adj);
+	if (hw->dev_caps.ts_dev_info.ll_phy_tmr_update) {
+		err = ice_ptp_prep_phy_adj_ll_e810(hw, adj);
+		if (err != -ETIMEDOUT)
+			return err;
+		ice_debug(hw, ICE_DBG_PTP, "LL adj timed out, falling
back to SBQ\n");
+	}

 	tmr_idx = hw->func_caps.ts_func_info.tmr_index_owned;

@@ -4882,15 +4883,12 @@ static int

ice_ptp_prep_phy_incval_ll_e810(struct ice_hw *hw, u64 incval)
 				       !FIELD_GET(REG_LL_PROXY_H_EXEC,
val),
 				       10, REG_LL_PROXY_H_TIMEOUT_US,
false, hw,
 				       REG_LL_PROXY_H);
-	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to prepare PHY timer
increment using low latency interface\n");
-		spin_unlock_irq(&params->atqbal_wq.lock);
-		return err;
-	}
-
 	spin_unlock_irq(&params->atqbal_wq.lock);

-	return 0;
+	if (err)
+		ice_debug(hw, ICE_DBG_PTP, "Failed to prepare PHY timer
increment
+using low latency interface\n");
+
+	return err;
 }

 /**

@@ -4908,8 +4906,12 @@ static int ice_ptp_prep_phy_incval_e810(struct

ice_hw *hw, u64 incval)
 	u8 tmr_idx;
 	int err;

-	if (hw->dev_caps.ts_dev_info.ll_phy_tmr_update)
-		return ice_ptp_prep_phy_incval_ll_e810(hw, incval);
+	if (hw->dev_caps.ts_dev_info.ll_phy_tmr_update) {
+		err = ice_ptp_prep_phy_incval_ll_e810(hw, incval);
+		if (err != -ETIMEDOUT)
+			return err;
+		ice_debug(hw, ICE_DBG_PTP, "LL incval timed out, falling
back to SBQ\n");
+	}

 	tmr_idx = hw->func_caps.ts_func_info.tmr_index_owned;
 	low = lower_32_bits(incval);

base-commit: 2d72c95ac8e2d1abccf671d95b94532a8b2abb24
--
2.43.0