[PATCH iwl-net v4] ice: fix missing dpll notifications for SW pins

[Petr Oros <poros@redhat.com>]

The SMA/U.FL pin redesign (commit 2dd5d03c77e2 ("ice: redesign dpll
sma/u.fl pins control")) introduced software-controlled pins that wrap
backing CGU input/output pins, but never updated the notification and
data paths to propagate pin events to these SW wrappers.

There are three problems:

1) ice_dpll_notify_changes() sends dpll_pin_change_ntf() only for the
   direct CGU input pin stored in d->active_input.  When the active
   input changes, SW pins (SMA/U.FL) that wrap the old or new active
   input never receive a change notification.  As a result, userspace
   consumers such as synce4l that monitor SMA pins via dpll netlink
   never learn when the pin state transitions (e.g. from SELECTABLE to
   CONNECTED).

2) ice_dpll_phase_offset_get() returns p->phase_offset for non-active
   SW pins, but this field is never updated for SW pins.  The PPS phase
   offset monitor updates the backing CGU input's phase_offset
   (p->input->phase_offset), not the SW pin's own field.  As a result
   non-active SW pins always report zero phase offset even when the
   backing CGU input has valid PPS measurements.

3) ice_dpll_pins_notify_mask() does not propagate phase offset change
   notifications to SW pins either.  When a HW CGU pin gets a phase
   offset change notification, the SMA/U.FL pin wrapping it is never
   notified, so userspace consumers (ts2phc, synce4l) monitoring SW
   pins via dpll netlink never receive phase offset updates.

Fix all three by:

 - In ice_dpll_phase_offset_get(), return the backing CGU input's
   phase_offset for input-direction SW pins instead of the SW pin's own
   (always zero) field.

 - Introduce ice_dpll_pin_ntf(), a thin wrapper around
   dpll_pin_change_ntf() that also sends notifications to any
   registered SMA/U.FL pin whose backing CGU input matches.  Replace
   all direct dpll_pin_change_ntf() calls in the periodic notification
   paths with ice_dpll_pin_ntf(), so SW pins are automatically notified
   whenever their backing HW pin is.

Fixes: 2dd5d03c77e2 ("ice: redesign dpll sma/u.fl pins control")
Signed-off-by: Petr Oros <poros@redhat.com>
---
v4:
 - expanded scope to also fix phase offset reporting and phase offset
   notifications for SW pins (problems 2 and 3 above)
 - replaced ice_dpll_sw_pin_needs_notify() with ice_dpll_pin_ntf(),
   a unified wrapper that covers all notification paths
 - squashed into a single patch
v3: https://lore.kernel.org/all/20260220140700.2910174-1-poros@redhat.com/
 - added kdoc for ice_dpll_sw_pin_needs_notify() helper
v2: https://lore.kernel.org/all/20260219131500.2271897-1-poros@redhat.com/
 - extracted ice_dpll_sw_pin_needs_notify() helper for readability
 - moved loop variable into for() scope
v1: https://lore.kernel.org/all/20260218211414.1411163-1-poros@redhat.com/
---
 drivers/net/ethernet/intel/ice/ice_dpll.c | 47 +++++++++++++++++------
 1 file changed, 36 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_dpll.c b/drivers/net/ethernet/intel/ice/ice_dpll.c
index 62f75701d65205..5cfa19da099bfc 100644
--- a/drivers/net/ethernet/intel/ice/ice_dpll.c
+++ b/drivers/net/ethernet/intel/ice/ice_dpll.c
@@ -1915,7 +1915,10 @@ ice_dpll_phase_offset_get(const struct dpll_pin *pin, void *pin_priv,
 				       d->active_input == p->input->pin))
 		*phase_offset = d->phase_offset * ICE_DPLL_PHASE_OFFSET_FACTOR;
 	else if (d->phase_offset_monitor_period)
-		*phase_offset = p->phase_offset * ICE_DPLL_PHASE_OFFSET_FACTOR;
+		*phase_offset = (p->input &&
+				 p->direction == DPLL_PIN_DIRECTION_INPUT ?
+				 p->input->phase_offset :
+				 p->phase_offset) * ICE_DPLL_PHASE_OFFSET_FACTOR;
 	else
 		*phase_offset = 0;
 	mutex_unlock(&pf->dplls.lock);
@@ -2609,6 +2612,27 @@ static u64 ice_generate_clock_id(struct ice_pf *pf)
 	return pci_get_dsn(pf->pdev);
 }
 
+/**
+ * ice_dpll_pin_ntf - notify pin change including any SW pin wrappers
+ * @dplls: pointer to dplls struct
+ * @pin: the dpll_pin that changed
+ *
+ * Send a change notification for @pin and for any registered SMA/U.FL pin
+ * whose backing CGU input matches @pin.
+ */
+static void ice_dpll_pin_ntf(struct ice_dplls *dplls, struct dpll_pin *pin)
+{
+	dpll_pin_change_ntf(pin);
+	for (int i = 0; i < ICE_DPLL_PIN_SW_NUM; i++) {
+		if (dplls->sma[i].pin && dplls->sma[i].input &&
+		    dplls->sma[i].input->pin == pin)
+			dpll_pin_change_ntf(dplls->sma[i].pin);
+		if (dplls->ufl[i].pin && dplls->ufl[i].input &&
+		    dplls->ufl[i].input->pin == pin)
+			dpll_pin_change_ntf(dplls->ufl[i].pin);
+	}
+}
+
 /**
  * ice_dpll_notify_changes - notify dpll subsystem about changes
  * @d: pointer do dpll
@@ -2617,6 +2641,7 @@ static u64 ice_generate_clock_id(struct ice_pf *pf)
  */
 static void ice_dpll_notify_changes(struct ice_dpll *d)
 {
+	struct ice_dplls *dplls = &d->pf->dplls;
 	bool pin_notified = false;
 
 	if (d->prev_dpll_state != d->dpll_state) {
@@ -2625,17 +2650,17 @@ static void ice_dpll_notify_changes(struct ice_dpll *d)
 	}
 	if (d->prev_input != d->active_input) {
 		if (d->prev_input)
-			dpll_pin_change_ntf(d->prev_input);
+			ice_dpll_pin_ntf(dplls, d->prev_input);
 		d->prev_input = d->active_input;
 		if (d->active_input) {
-			dpll_pin_change_ntf(d->active_input);
+			ice_dpll_pin_ntf(dplls, d->active_input);
 			pin_notified = true;
 		}
 	}
 	if (d->prev_phase_offset != d->phase_offset) {
 		d->prev_phase_offset = d->phase_offset;
 		if (!pin_notified && d->active_input)
-			dpll_pin_change_ntf(d->active_input);
+			ice_dpll_pin_ntf(dplls, d->active_input);
 	}
 }
 
@@ -2664,6 +2689,7 @@ static bool ice_dpll_is_pps_phase_monitor(struct ice_pf *pf)
 
 /**
  * ice_dpll_pins_notify_mask - notify dpll subsystem about bulk pin changes
+ * @dplls: pointer to dplls struct
  * @pins: array of ice_dpll_pin pointers registered within dpll subsystem
  * @pin_num: number of pins
  * @phase_offset_ntf_mask: bitmask of pin indexes to notify
@@ -2673,15 +2699,14 @@ static bool ice_dpll_is_pps_phase_monitor(struct ice_pf *pf)
  *
  * Context: Must be called while pf->dplls.lock is released.
  */
-static void ice_dpll_pins_notify_mask(struct ice_dpll_pin *pins,
+static void ice_dpll_pins_notify_mask(struct ice_dplls *dplls,
+				      struct ice_dpll_pin *pins,
 				      u8 pin_num,
 				      u32 phase_offset_ntf_mask)
 {
-	int i = 0;
-
-	for (i = 0; i < pin_num; i++)
-		if (phase_offset_ntf_mask & (1 << i))
-			dpll_pin_change_ntf(pins[i].pin);
+	for (int i = 0; i < pin_num; i++)
+		if (phase_offset_ntf_mask & BIT(i))
+			ice_dpll_pin_ntf(dplls, pins[i].pin);
 }
 
 /**
@@ -2857,7 +2882,7 @@ static void ice_dpll_periodic_work(struct kthread_work *work)
 	ice_dpll_notify_changes(de);
 	ice_dpll_notify_changes(dp);
 	if (phase_offset_ntf)
-		ice_dpll_pins_notify_mask(d->inputs, d->num_inputs,
+		ice_dpll_pins_notify_mask(d, d->inputs, d->num_inputs,
 					  phase_offset_ntf);
 
 resched:
-- 
2.52.0