Change the default to not use packet counters to generate rx interrupts.

Rely solely on the timer based mechanism.

Update man page to reflect this change.

MFC after:	1 week

3 files changed, 12 insertions, 10 deletions

diff --git a/share/man/man4/cxgbe.4 b/share/man/man4/cxgbe.4
index 88d42e3..a84ae55 100644
--- a/share/man/man4/cxgbe.4
+++ b/share/man/man4/cxgbe.4
@@ -1,4 +1,4 @@
-.\" Copyright (c) 2011, Chelsio Inc
+.\" Copyright (c) 2011-2012, Chelsio Inc
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
@@ -145,10 +145,9 @@ dev.cxgbe.X.holdoff_tmr_idx sysctl.
 The packet-count index value to use to delay interrupts.
 The packet-count list has the values 1, 8, 16, and 32 by default
 and the index selects a value from this list.
-The default value is 2 for both 10Gb and 1Gb ports, which means 16
-packets (or the holdoff timer going off) before an interrupt is
-generated.
--1 disables packet counting.
+The default value is -1 for both 10Gb and 1Gb ports, which means packet
+counting is disabled and interrupts are generated based solely on the
+holdoff timer value.
 Different cxgbe interfaces can be assigned different values via the
 dev.cxgbe.X.holdoff_pktc_idx sysctl.
 This sysctl works only when the interface has never been marked up (as done by
diff --git a/sys/dev/cxgbe/t4_main.c b/sys/dev/cxgbe/t4_main.c
index 7509a02..874a6ad 100644
--- a/sys/dev/cxgbe/t4_main.c
+++ b/sys/dev/cxgbe/t4_main.c
@@ -174,7 +174,7 @@ TUNABLE_INT("hw.cxgbe.nofldrxq1g", &t4_nofldrxq1g);
 static int t4_tmr_idx_10g = TMR_IDX_10G;
 TUNABLE_INT("hw.cxgbe.holdoff_timer_idx_10G", &t4_tmr_idx_10g);
 
-#define PKTC_IDX_10G 2
+#define PKTC_IDX_10G (-1)
 static int t4_pktc_idx_10g = PKTC_IDX_10G;
 TUNABLE_INT("hw.cxgbe.holdoff_pktc_idx_10G", &t4_pktc_idx_10g);
 
@@ -182,7 +182,7 @@ TUNABLE_INT("hw.cxgbe.holdoff_pktc_idx_10G", &t4_pktc_idx_10g);
 static int t4_tmr_idx_1g = TMR_IDX_1G;
 TUNABLE_INT("hw.cxgbe.holdoff_timer_idx_1G", &t4_tmr_idx_1g);
 
-#define PKTC_IDX_1G 2
+#define PKTC_IDX_1G (-1)
 static int t4_pktc_idx_1g = PKTC_IDX_1G;
 TUNABLE_INT("hw.cxgbe.holdoff_pktc_idx_1G", &t4_pktc_idx_1g);
 
diff --git a/sys/dev/cxgbe/t4_sge.c b/sys/dev/cxgbe/t4_sge.c
index 41630e4..8f39f10 100644
--- a/sys/dev/cxgbe/t4_sge.c
+++ b/sys/dev/cxgbe/t4_sge.c
@@ -1420,9 +1420,12 @@ init_iq(struct sge_iq *iq, struct adapter *sc, int tmr_idx, int pktc_idx,
 
 	iq->flags = 0;
 	iq->adapter = sc;
-	iq->intr_params = V_QINTR_TIMER_IDX(tmr_idx) |
-	    V_QINTR_CNT_EN(pktc_idx >= 0);
-	iq->intr_pktc_idx = pktc_idx;
+	iq->intr_params = V_QINTR_TIMER_IDX(tmr_idx);
+	iq->intr_pktc_idx = SGE_NCOUNTERS - 1;
+	if (pktc_idx >= 0) {
+		iq->intr_params |= F_QINTR_CNT_EN;
+		iq->intr_pktc_idx = pktc_idx;
+	}
 	iq->qsize = roundup(qsize, 16);		/* See FW_IQ_CMD/iqsize */
 	iq->esize = max(esize, 16);		/* See FW_IQ_CMD/iqesize */
 	strlcpy(iq->lockname, name, sizeof(iq->lockname));