From: Hendrik Brueckner <brueckner@redhat.com>
Date: Tue, 2 Feb 2010 14:10:50 -0500
Subject: [s390] qeth: set default BLKT settings by OSA hw level
Message-id: <20100202141050.GB9164@redhat.com>
Patchwork-id: 23099
O-Subject: [RHEL5.6 PATCH 1/1] [s390] qeth: set default BLKT settings
	dependend on OSA hw level
Bugzilla: 559621
RH-Acked-by: David S. Miller <davem@redhat.com>
RH-Acked-by: Pete Zaitcev <zaitcev@redhat.com>

Description
-----------
New OSA Express 3 cards gets configured with values matching old
hardware levels.  This increases CPU load when receiving network
packets.

To solve the performance impact, probe the correct hardware level and
set the BLKT (blocking threshold) settings accordingly.

Bugzilla
--------
BZ 559621
https://bugzilla.redhat.com/show_bug.cgi?id=559621

Upstream status of the patch
----------------------------
The patch will be upstream as of kernel version 2.6.34
http://git.kernel.org/?p=linux/kernel/git/davem/net-next-2.6.git;a=commitdiff;h=a60389abaab92213c79790e074ff6bc36ac0ebe5

Test status
-----------
The patch has been tested and fixes the problem.
The fix has been verified by the IBM test department.


diff --git a/drivers/s390/net/qeth_main.c b/drivers/s390/net/qeth_main.c
index 584af9b..e345818 100644
--- a/drivers/s390/net/qeth_main.c
+++ b/drivers/s390/net/qeth_main.c
@@ -1167,6 +1167,58 @@ qeth_determine_card_type(struct qeth_card *card)
 	return -ENOENT;
 }
 
+static void qeth_configure_unitaddr(struct qeth_card *card, char *prcd)
+{
+	QETH_DBF_TEXT(setup, 2, "getunit");
+	card->info.chpid = prcd[30];
+	card->info.unit_addr2 = prcd[31];
+	card->info.cula = prcd[63];
+	card->info.guestlan = ((prcd[0x10] == _ascebc['V']) &&
+			       (prcd[0x11] == _ascebc['M']));
+}
+
+static void qeth_configure_blkt_default(struct qeth_card *card, char *prcd) {
+	QETH_DBF_TEXT(setup, 2, "cfgblkt");
+
+	if (prcd[74] == 0xF0 && prcd[75] == 0xF0 && prcd[76] == 0xF5) {
+		card->info.blkt.time_total = 250;
+		card->info.blkt.inter_packet = 5;
+		card->info.blkt.inter_packet_jumbo = 15;
+	} else {
+		card->info.blkt.time_total = 0;
+		card->info.blkt.inter_packet = 0;
+		card->info.blkt.inter_packet_jumbo = 0;
+	}
+}
+
+static void qeth_determine_capabilities(struct qeth_card *card)
+{
+	int rc;
+	int length;
+	char *prcd;
+
+	QETH_DBF_TEXT(setup, 2, "detcapab");
+	rc = ccw_device_set_online(CARD_DDEV(card));
+	if (rc) {
+		QETH_DBF_TEXT_(setup, 2, "3err%d", rc);
+		goto out;
+	}
+
+	rc = read_conf_data(CARD_DDEV(card), (void **) &prcd, &length);
+	if (rc) {
+		QETH_DBF_TEXT_(setup, 2, "5err%d", rc);
+		goto out_offline;
+	}
+	qeth_configure_unitaddr(card, prcd);
+	qeth_configure_blkt_default(card, prcd);
+	kfree(prcd);
+
+out_offline:
+	ccw_device_set_offline(CARD_DDEV(card));
+out:
+	return;
+}
+
 static int
 qeth_probe_device(struct ccwgroup_device *gdev)
 {
@@ -1221,31 +1273,14 @@ qeth_probe_device(struct ccwgroup_device *gdev)
 	write_lock_irqsave(&qeth_card_list.rwlock, flags);
 	list_add_tail(&card->list, &qeth_card_list.list);
 	write_unlock_irqrestore(&qeth_card_list.rwlock, flags);
+
+	qeth_determine_capabilities(card);
+
 	return rc;
 }
 
 
-static int
-qeth_get_unitaddr(struct qeth_card *card)
-{
- 	int length;
-	char *prcd;
-	int rc;
 
-	QETH_DBF_TEXT(setup, 2, "getunit");
-	rc = read_conf_data(CARD_DDEV(card), (void **) &prcd, &length);
-	if (rc) {
-		PRINT_ERR("read_conf_data for device %s returned %i\n",
-			  CARD_DDEV_ID(card), rc);
-		return rc;
-	}
-	card->info.chpid = prcd[30];
-	card->info.unit_addr2 = prcd[31];
-	card->info.cula = prcd[63];
-	card->info.guestlan = ((prcd[0x10] == _ascebc['V']) &&
-			       (prcd[0x11] == _ascebc['M']));
-	return 0;
-}
 
 static void
 qeth_init_tokens(struct qeth_card *card)
@@ -6675,11 +6710,6 @@ retry:
 		else
 			goto retry;
 	}
-	rc = qeth_get_unitaddr(card);
-	if (rc) {
-		QETH_DBF_TEXT_(setup, 2, "2err%d", rc);
-		return rc;
-	}
 	mpno = qdio_get_ssqd_pct(CARD_DDEV(card));
 	if (mpno)
 		mpno = min(mpno - 1, QETH_MAX_PORTNO);
diff --git a/drivers/s390/net/qeth_sys.c b/drivers/s390/net/qeth_sys.c
index 15c818f..4102f87 100644
--- a/drivers/s390/net/qeth_sys.c
+++ b/drivers/s390/net/qeth_sys.c
@@ -870,7 +870,7 @@ qeth_dev_blkt_total_store(struct device *dev, struct device_attribute *attr, con
 	struct qeth_card *card = dev->driver_data;
 
 	return qeth_dev_blkt_store(card, buf, count,
-				   &card->info.blkt.time_total,1000);
+				   &card->info.blkt.time_total,5000);
 }
 
 
@@ -893,7 +893,7 @@ qeth_dev_blkt_inter_store(struct device *dev, struct device_attribute *attr, con
 	struct qeth_card *card = dev->driver_data;
 
 	return qeth_dev_blkt_store(card, buf, count,
-				   &card->info.blkt.inter_packet,100);
+				   &card->info.blkt.inter_packet,1000);
 }
 
 static DEVICE_ATTR(inter, 0644, qeth_dev_blkt_inter_show,
@@ -915,7 +915,7 @@ qeth_dev_blkt_inter_jumbo_store(struct device *dev, struct device_attribute *att
 	struct qeth_card *card = dev->driver_data;
 
 	return qeth_dev_blkt_store(card, buf, count,
-				   &card->info.blkt.inter_packet_jumbo,100);
+				   &card->info.blkt.inter_packet_jumbo,1000);
 }
 
 static DEVICE_ATTR(inter_jumbo, 0644, qeth_dev_blkt_inter_jumbo_show,