[Intel-wired-lan] [PATCH v3 iwl-next 8/9] ice: restore timestamp configuration after reset

[Karol Kolacinski <karol.kolacinski@intel.com>]

From: Jacob Keller <jacob.e.keller@intel.com>

The driver calls ice_ptp_cfg_timestamp() during
ice_ptp_prepare_for_reset() to disable timestamping while the device is
resetting. It then attempts to restore timestamp configuration at the
end of ice_rebuild(). However, it currently forcibly calls
ice_ptp_cfg_timestamp() with a value of true when the device is not E810
and is the clock owner, while calling ice_ptp_cfg_timestamp() with a
value of false for all other devices.

This incorrectly forcibly disables timestamping on all ports except the
clock owner.

This was not detected previously due to a quirk of the LinuxPTP ptp4l
application. If ptp4l detects a missing timestamp, it enters a fault
state and performs recovery logic which includes executing SIOCSHWTSTAMP
again, restoring the now accidentally cleared configuration.

Not every application does this, and for these applications, timestamps
will mysteriously stop after a PF reset, without being restored until an
application restart.

Fix this by replacing ice_ptp_cfg_timestamp() with two new functions:

1) ice_ptp_disable_timestamp_mode() which unconditionally disables the
   timestamping logic in ice_ptp_prepare_for_reset() and
   ice_ptp_release()

2) ice_ptp_restore_timestamp_mode() which calls
   ice_ptp_restore_tx_interrupt() to restore Tx timestamping
   configuration, calls ice_set_rx_tstamp() to restore Rx timestamping
   configuration, and issues an immediate TSYN_TX interrupt to ensure
   that timestamps which may have occurred during the device reset get
   processed.

This obsoletes the ice_set_tx_tstamp() function which can now be safely
removed.

With this change, all devices should now restore Tx and Rx timestamping
functionality correctly after a PF reset without application
intervention.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_main.c | 10 +---
 drivers/net/ethernet/intel/ice/ice_ptp.c  | 72 +++++++++++++++++------
 drivers/net/ethernet/intel/ice/ice_ptp.h  |  4 +-
 3 files changed, 59 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 031f91fb2b0d..06b348f5dadb 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -7368,14 +7368,8 @@ static void ice_rebuild(struct ice_pf *pf, enum ice_reset_req reset_type)
 		goto err_vsi_rebuild;
 	}
 
-	/* configure PTP timestamping after VSI rebuild */
-	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags)) {
-		if (pf->ptp.tx_interrupt_mode == ICE_PTP_TX_INTERRUPT_SELF)
-			ice_ptp_cfg_timestamp(pf, false);
-		else if (pf->ptp.tx_interrupt_mode == ICE_PTP_TX_INTERRUPT_ALL)
-			/* for E82x PHC owner always need to have interrupts */
-			ice_ptp_cfg_timestamp(pf, true);
-	}
+	/* Restore timestamp mode settings after VSI rebuild */
+	ice_ptp_restore_timestamp_mode(pf);
 
 	err = ice_vsi_rebuild_by_type(pf, ICE_VSI_SWITCHDEV_CTRL);
 	if (err) {
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index dac77bff4d20..8f783004f4a9 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -299,14 +299,27 @@ static void ice_ptp_cfg_tx_interrupt(struct ice_pf *pf, bool on)
 }
 
 /**
- * ice_set_tx_tstamp - Enable or disable Tx timestamping
- * @pf: The PF pointer to search in
- * @on: bool value for whether timestamps are enabled or disabled
+ * ice_ptp_restore_tx_interrupt - Restore Tx timestamp interrupt after reset
+ * @pf: Board private structure
  */
-static void ice_set_tx_tstamp(struct ice_pf *pf, bool on)
+static void ice_ptp_restore_tx_interrupt(struct ice_pf *pf)
 {
-	if (pf->ptp.tx_interrupt_mode == ICE_PTP_TX_INTERRUPT_SELF)
-		ice_ptp_cfg_tx_interrupt(pf, on);
+	bool enable;
+
+	switch (pf->ptp.tx_interrupt_mode) {
+	case ICE_PTP_TX_INTERRUPT_ALL:
+		enable = true;
+		break;
+	case ICE_PTP_TX_INTERRUPT_NONE:
+		enable = false;
+		break;
+	case ICE_PTP_TX_INTERRUPT_SELF:
+	default:
+		enable = pf->ptp.tstamp_config.tx_type == HWTSTAMP_TX_ON;
+		break;
+	}
+
+	ice_ptp_cfg_tx_interrupt(pf, enable);
 }
 
 /**
@@ -332,17 +345,41 @@ static void ice_set_rx_tstamp(struct ice_pf *pf, bool on)
 }
 
 /**
- * ice_ptp_cfg_timestamp - Configure timestamp for init/deinit
+ * ice_ptp_disable_timestamp_mode - Disable current timestamp mode
  * @pf: Board private structure
- * @ena: bool value to enable or disable time stamp
  *
- * This function will configure timestamping during PTP initialization
- * and deinitialization
+ * Called during preparation for reset to temporarily disable timestamping on
+ * the device. Called during remove to disable timestamping while cleaning up
+ * driver resources.
  */
-void ice_ptp_cfg_timestamp(struct ice_pf *pf, bool ena)
+static void ice_ptp_disable_timestamp_mode(struct ice_pf *pf)
 {
-	ice_set_tx_tstamp(pf, ena);
-	ice_set_rx_tstamp(pf, ena);
+	ice_ptp_cfg_tx_interrupt(pf, false);
+	ice_set_rx_tstamp(pf, false);
+}
+
+/**
+ * ice_ptp_restore_timestamp_mode - Restore timestamp configuration
+ * @pf: Board private structure
+ *
+ * Called at the end of rebuild to restore timestamp configuration after
+ * a device reset.
+ */
+void ice_ptp_restore_timestamp_mode(struct ice_pf *pf)
+{
+	struct ice_hw *hw = &pf->hw;
+	bool enable_rx;
+
+	ice_ptp_restore_tx_interrupt(pf);
+
+	enable_rx = pf->ptp.tstamp_config.rx_filter == HWTSTAMP_FILTER_ALL;
+	ice_set_rx_tstamp(pf, enable_rx);
+
+	/* Trigger an immediate software interrupt to ensure that timestamps
+	 * which occurred during reset are handled now.
+	 */
+	wr32(hw, PFINT_OICR, PFINT_OICR_TSYN_TX_M);
+	ice_flush(hw);
 }
 
 /**
@@ -2048,11 +2085,9 @@ ice_ptp_set_timestamp_mode(struct ice_pf *pf, struct hwtstamp_config *config)
 {
 	switch (config->tx_type) {
 	case HWTSTAMP_TX_OFF:
-		ice_set_tx_tstamp(pf, false);
 		pf->ptp.tstamp_config.tx_type = HWTSTAMP_TX_OFF;
 		break;
 	case HWTSTAMP_TX_ON:
-		ice_set_tx_tstamp(pf, true);
 		pf->ptp.tstamp_config.tx_type = HWTSTAMP_TX_ON;
 		break;
 	default:
@@ -2085,6 +2120,9 @@ ice_ptp_set_timestamp_mode(struct ice_pf *pf, struct hwtstamp_config *config)
 		return -ERANGE;
 	}
 
+	/* Make sure interrupt settings are restored */
+	ice_ptp_restore_tx_interrupt(pf);
+
 	return 0;
 }
 
@@ -2464,7 +2502,7 @@ ice_ptp_prepare_for_reset(struct ice_pf *pf, enum ice_reset_req reset_type)
 	ptp->state = ICE_PTP_RESETTING;
 
 	/* Disable timestamping for both Tx and Rx */
-	ice_ptp_cfg_timestamp(pf, false);
+	ice_ptp_disable_timestamp_mode(pf);
 
 	kthread_cancel_delayed_work_sync(&ptp->work);
 
@@ -3117,7 +3155,7 @@ void ice_ptp_release(struct ice_pf *pf)
 	pf->ptp.state = ICE_PTP_UNINIT;
 
 	/* Disable timestamping for both Tx and Rx */
-	ice_ptp_cfg_timestamp(pf, false);
+	ice_ptp_disable_timestamp_mode(pf);
 
 	ice_ptp_remove_auxbus_device(pf);
 
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index 210e2a1b35a5..bd5826ba3576 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -306,7 +306,7 @@ int ice_ptp_clock_index(struct ice_pf *pf);
 struct ice_pf;
 int ice_ptp_set_ts_config(struct ice_pf *pf, struct ifreq *ifr);
 int ice_ptp_get_ts_config(struct ice_pf *pf, struct ifreq *ifr);
-void ice_ptp_cfg_timestamp(struct ice_pf *pf, bool ena);
+void ice_ptp_restore_timestamp_mode(struct ice_pf *pf);
 
 void ice_ptp_extts_event(struct ice_pf *pf);
 s8 ice_ptp_request_ts(struct ice_ptp_tx *tx, struct sk_buff *skb);
@@ -332,7 +332,7 @@ static inline int ice_ptp_get_ts_config(struct ice_pf *pf, struct ifreq *ifr)
 	return -EOPNOTSUPP;
 }
 
-static inline void ice_ptp_cfg_timestamp(struct ice_pf *pf, bool ena) { }
+static inline void ice_ptp_restore_timestamp_mode(struct ice_pf *pf) { }
 
 static inline void ice_ptp_extts_event(struct ice_pf *pf) { }
 static inline s8
-- 
2.39.2

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