[PATCH iwl-net 3/4] ice: cancel E82x offset verification work during reset preparation

[Przemyslaw Korba <przemyslaw.korba@intel.com>]

From: Karol Kolacinski <karol.kolacinski@intel.com>

Cancel the offset verification delayed work (ov_work) during PTP reset
preparation to prevent it from running concurrently with the reset
sequence.

Without this, ice_ptp_wait_for_offsets() can execute during a reset,
find that ice_is_reset_in_progress() is true, and re-queue itself in a
tight loop. Meanwhile, the reset path in ice_ptp_rebuild_owner() calls
ice_ptp_port_phy_restart(), which starts a new ov_work. This results in
two ov_work instances running simultaneously, racing over the PHY offset
registers and the calibrating flag.

Cancel ov_work in ice_ptp_prepare_for_reset() alongside the existing
cancellation of the Tx tracker. The comment in the existing code already
documents that ov_work interference during reset is a concern but only
cancels it during ice_ptp_release().

Fixes: 4809671015a1 ("ice: Fix E810 PTP reset flow")
Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: Przemyslaw Korba <przemyslaw.korba@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 9d9d9958fe5c..e0be88024ac3 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -3042,6 +3042,14 @@ void ice_ptp_prepare_for_reset(struct ice_pf *pf, enum ice_reset_req reset_type)
 	if (reset_type == ICE_RESET_PFR)
 		return;
 
+	/* Cancel the offset verification work for E82x before releasing the
+	 * Tx tracker. If ov_work is running during reset, it may issue
+	 * sideband queue commands that will fail or timeout, and may
+	 * reference state that is being torn down.
+	 */
+	if (hw->mac_type == ICE_MAC_GENERIC)
+		kthread_cancel_delayed_work_sync(&ptp->port.ov_work);
+
 	if (ice_pf_src_tmr_owned(pf) && hw->mac_type == ICE_MAC_GENERIC_3K_E825)
 		ice_ptp_prepare_rebuild_sec(pf, false, reset_type);
 
-- 
2.43.0