ionic: report users coalesce request

The user's request for an interrupt coalescing value gets
translated into a hardware value to be used with the NIC,
and was getting reported back based on the hw value, which,
due to hw tic resolution, could be reported as a different
number than what the user originally asked for.  This code
now tracks both the user request and what was put into the
hardware so we can report back to the user what they
requested.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/pensando/ionic/ionic_ethtool.c

@@ -372,7 +372,6 @@ static int ionic_set_coalesce(struct net_device *netdev,
 	struct ionic_identity *ident;
 	struct ionic_qcq *qcq;
 	unsigned int i;
-	u32 usecs;
 	u32 coal;
 
 	if (coalesce->rx_max_coalesced_frames ||
@@ -410,26 +409,27 @@ static int ionic_set_coalesce(struct net_device *netdev,
 		return -EINVAL;
 	}
 
+	/* Convert the usec request to a HW useable value.  If they asked
+	 * for non-zero and it resolved to zero, bump it up
+	 */
 	coal = ionic_coal_usec_to_hw(lif->ionic, coalesce->rx_coalesce_usecs);
-
-	if (coal > IONIC_INTR_CTRL_COAL_MAX)
-		return -ERANGE;
-
-	/* If they asked for non-zero and it resolved to zero, bump it up */
 	if (!coal && coalesce->rx_coalesce_usecs)
 		coal = 1;
 
-	/* Convert it back to get device resolution */
-	usecs = ionic_coal_hw_to_usec(lif->ionic, coal);
+	if (coal > IONIC_INTR_CTRL_COAL_MAX)
+		return -ERANGE;
 
-	if (usecs != lif->rx_coalesce_usecs) {
-		lif->rx_coalesce_usecs = usecs;
+	/* Save the new value */
+	lif->rx_coalesce_usecs = coalesce->rx_coalesce_usecs;
+	if (coal != lif->rx_coalesce_hw) {
+		lif->rx_coalesce_hw = coal;
 
 		if (test_bit(IONIC_LIF_UP, lif->state)) {
 			for (i = 0; i < lif->nxqs; i++) {
 				qcq = lif->rxqcqs[i].qcq;
 				ionic_intr_coal_init(lif->ionic->idev.intr_ctrl,
-						     qcq->intr.index, coal);
+						     qcq->intr.index,
+						     lif->rx_coalesce_hw);
 			}
 		}
 	}

drivers/net/ethernet/pensando/ionic/ionic_lif.c

@@ -1430,7 +1430,6 @@ static int ionic_txrx_alloc(struct ionic_lif *lif)
 	unsigned int flags;
 	unsigned int i;
 	int err = 0;
-	u32 coal;
 
 	flags = IONIC_QCQ_F_TX_STATS | IONIC_QCQ_F_SG;
 	for (i = 0; i < lif->nxqs; i++) {
@@ -1447,7 +1446,6 @@ static int ionic_txrx_alloc(struct ionic_lif *lif)
 	}
 
 	flags = IONIC_QCQ_F_RX_STATS | IONIC_QCQ_F_INTR;
-	coal = ionic_coal_usec_to_hw(lif->ionic, lif->rx_coalesce_usecs);
 	for (i = 0; i < lif->nxqs; i++) {
 		err = ionic_qcq_alloc(lif, IONIC_QTYPE_RXQ, i, "rx", flags,
 				      lif->nrxq_descs,
@@ -1460,7 +1458,8 @@ static int ionic_txrx_alloc(struct ionic_lif *lif)
 		lif->rxqcqs[i].qcq->stats = lif->rxqcqs[i].stats;
 
 		ionic_intr_coal_init(lif->ionic->idev.intr_ctrl,
-				     lif->rxqcqs[i].qcq->intr.index, coal);
+				     lif->rxqcqs[i].qcq->intr.index,
+				     lif->rx_coalesce_hw);
 		ionic_link_qcq_interrupts(lif->rxqcqs[i].qcq,
 					  lif->txqcqs[i].qcq);
 	}
@@ -1640,7 +1639,6 @@ static struct ionic_lif *ionic_lif_alloc(struct ionic *ionic, unsigned int index
 	struct net_device *netdev;
 	struct ionic_lif *lif;
 	int tbl_sz;
-	u32 coal;
 	int err;
 
 	netdev = alloc_etherdev_mqs(sizeof(*lif),
@@ -1671,8 +1669,9 @@ static struct ionic_lif *ionic_lif_alloc(struct ionic *ionic, unsigned int index
 	lif->nrxq_descs = IONIC_DEF_TXRX_DESC;
 
 	/* Convert the default coalesce value to actual hw resolution */
-	coal = ionic_coal_usec_to_hw(lif->ionic, IONIC_ITR_COAL_USEC_DEFAULT);
-	lif->rx_coalesce_usecs = ionic_coal_hw_to_usec(lif->ionic, coal);
+	lif->rx_coalesce_usecs = IONIC_ITR_COAL_USEC_DEFAULT;
+	lif->rx_coalesce_hw = ionic_coal_hw_to_usec(lif->ionic,
+						    lif->rx_coalesce_usecs);
 
 	snprintf(lif->name, sizeof(lif->name), "lif%u", index);
 

drivers/net/ethernet/pensando/ionic/ionic_lif.h

@@ -175,7 +175,9 @@ struct ionic_lif {
 	unsigned long *dbid_inuse;
 	unsigned int dbid_count;
 	struct dentry *dentry;
-	u32 rx_coalesce_usecs;
+	u32 rx_coalesce_usecs;		/* what the user asked for */
+	u32 rx_coalesce_hw;		/* what the hw is using */
+
 	u32 flags;
 	struct work_struct tx_timeout_work;
 };