igc: Fix Rx timestamp disabling

When Rx timestamping is enabled, we set the timestamp bit in SRRCTL
register for each queue, but we don't clear it when disabling. This
patch fixes igc_ptp_disable_rx_timestamp() accordingly.

Also, this patch gets rid of igc_ptp_enable_tstamp_rxqueue() and
igc_ptp_enable_tstamp_all_rxqueues() and move their logic into
igc_ptp_enable_rx_timestamp() to keep the enable and disable
helpers symmetric.
Signed-off-by: Andre Guedes <andre.guedes@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igc/igc_ptp.c

@@ -205,47 +205,20 @@ void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va,
 		ktime_sub_ns(skb_hwtstamps(skb)->hwtstamp, adjust);
 }
 
-/**
- * igc_ptp_enable_tstamp_rxqueue - Enable RX timestamp for a queue
- * @rx_ring: Pointer to RX queue
- * @timer: Index for timer
- *
- * This function enables RX timestamping for a queue, and selects
- * which 1588 timer will provide the timestamp.
- */
-static void igc_ptp_enable_tstamp_rxqueue(struct igc_adapter *adapter,
-					  struct igc_ring *rx_ring, u8 timer)
-{
-	struct igc_hw *hw = &adapter->hw;
-	int reg_idx = rx_ring->reg_idx;
-	u32 srrctl = rd32(IGC_SRRCTL(reg_idx));
-
-	srrctl |= IGC_SRRCTL_TIMESTAMP;
-	srrctl |= IGC_SRRCTL_TIMER1SEL(timer);
-	srrctl |= IGC_SRRCTL_TIMER0SEL(timer);
-
-	wr32(IGC_SRRCTL(reg_idx), srrctl);
-}
-
-static void igc_ptp_enable_tstamp_all_rxqueues(struct igc_adapter *adapter,
-					       u8 timer)
-{
-	int i;
-
-	for (i = 0; i < adapter->num_rx_queues; i++) {
-		struct igc_ring *ring = adapter->rx_ring[i];
-
-		igc_ptp_enable_tstamp_rxqueue(adapter, ring, timer);
-	}
-}
-
 static void igc_ptp_disable_rx_timestamp(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
 	u32 val;
+	int i;
 
 	wr32(IGC_TSYNCRXCTL, 0);
 
+	for (i = 0; i < adapter->num_rx_queues; i++) {
+		val = rd32(IGC_SRRCTL(i));
+		val &= ~IGC_SRRCTL_TIMESTAMP;
+		wr32(IGC_SRRCTL(i), val);
+	}
+
 	val = rd32(IGC_RXPBS);
 	val &= ~IGC_RXPBS_CFG_TS_EN;
 	wr32(IGC_RXPBS, val);
@@ -255,14 +228,21 @@ static void igc_ptp_enable_rx_timestamp(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
 	u32 val;
+	int i;
 
 	val = rd32(IGC_RXPBS);
 	val |= IGC_RXPBS_CFG_TS_EN;
 	wr32(IGC_RXPBS, val);
 
-	/* FIXME: For now, only support retrieving RX timestamps from timer 0
+	for (i = 0; i < adapter->num_rx_queues; i++) {
+		val = rd32(IGC_SRRCTL(i));
+		/* FIXME: For now, only support retrieving RX timestamps from
+		 * timer 0.
 		 */
-	igc_ptp_enable_tstamp_all_rxqueues(adapter, 0);
+		val |= IGC_SRRCTL_TIMER1SEL(0) | IGC_SRRCTL_TIMER0SEL(0) |
+		       IGC_SRRCTL_TIMESTAMP;
+		wr32(IGC_SRRCTL(i), val);
+	}
 
 	val = IGC_TSYNCRXCTL_ENABLED | IGC_TSYNCRXCTL_TYPE_ALL |
 	      IGC_TSYNCRXCTL_RXSYNSIG;