From: Scott Moser <smoser@redhat.com>
Date: Tue, 23 Oct 2007 15:56:57 -0400
Subject: [net] ibmveth: fix rx pool deactivate oops
Message-id: 1193169420229-do-send-email-smoser@redhat.com
O-Subject: [PATCH RHEL5u2] bz250827 Jumbo frames cannot be enabled on ibmveth [1/3]
Bugzilla: 250827

Description:
-----------
Jumbo frames cannot be enabled on ibmveth. For example, adding MTU=9000 to
/etc/sysconfig/network-scripts/ifcfg-eth1 does not work since receive
buffer pools are not getting allocated. When attempting to use the ibmveth
sysfs interface to allocate the buffer pools prior to activating the
interface, an oops resulted.

Currently (2.6.18-52.el5), with inf=eth1 and mtu=9000 :
- ip link set dev $inf mtu $mtu
 fails with: SIOCSIFMTU: Invalid argument
- echo 1 > /sys/bus/vio/devices/30000004/pool3/active
 and
  echo 65536 > /sys/class/net/$i/device/pool0/size
 drops into xmon

The patch below fixes the listed crashes above and makes 'ip' able to set
the mtu as it should.

commit 76b9cfccb39f542ce48a79b9ad50af25e422506c
Author: Brian King <brking@linux.vnet.ibm.com>
Date:   Fri Aug 3 13:55:19 2007 +1000

ibmveth: Fix rx pool deactivate oops

This fixes an oops which can occur when trying to deallocate receive
buffer pools using sysfs with the ibmveth driver.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

Acked-by: Pete Zaitcev <zaitcev@redhat.com>
---
 drivers/net/ibmveth.c |   24 ++++++++++++++----------
 drivers/net/ibmveth.h |    3 ---
 2 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ibmveth.c b/drivers/net/ibmveth.c
index 9d7d9d8..fbb2d81 100644
--- a/drivers/net/ibmveth.c
+++ b/drivers/net/ibmveth.c
@@ -1260,24 +1260,28 @@ const char * buf, size_t count)
 			int i;
 			/* Make sure there is a buffer pool with buffers that
 			   can hold a packet of the size of the MTU */
-			for(i = 0; i<IbmVethNumBufferPools; i++) {
+			for (i = 0; i < IbmVethNumBufferPools; i++) {
 				if (pool == &adapter->rx_buff_pool[i])
 					continue;
 				if (!adapter->rx_buff_pool[i].active)
 					continue;
-				if (mtu < adapter->rx_buff_pool[i].buff_size) {
-					pool->active = 0;
-					h_free_logical_lan_buffer(adapter->
-								  vdev->
-								  unit_address,
-								  pool->
-								  buff_size);
-				}
+				if (mtu <= adapter->rx_buff_pool[i].buff_size)
+					break;
 			}
-			if (pool->active) {
+
+			if (i == IbmVethNumBufferPools) {
 				ibmveth_error_printk("no active pool >= MTU\n");
 				return -EPERM;
 			}
+
+			pool->active = 0;
+			if (netif_running(netdev)) {
+				adapter->pool_config = 1;
+				ibmveth_close(netdev);
+				adapter->pool_config = 0;
+				if ((rc = ibmveth_open(netdev)))
+					return rc;
+			}
 		}
 	} else if (attr == &veth_num_attr) {
 		if (value <= 0 || value > IBMVETH_MAX_POOL_COUNT)
diff --git a/drivers/net/ibmveth.h b/drivers/net/ibmveth.h
index 8385bf8..413002f 100644
--- a/drivers/net/ibmveth.h
+++ b/drivers/net/ibmveth.h
@@ -70,9 +70,6 @@
 #define h_change_logical_lan_mac(ua, mac) \
   plpar_hcall_norets(H_CHANGE_LOGICAL_LAN_MAC, ua, mac)
 
-#define h_free_logical_lan_buffer(ua, bufsize) \
-  plpar_hcall_norets(H_FREE_LOGICAL_LAN_BUFFER, ua, bufsize)
-
 #define IbmVethNumBufferPools 5
 #define IBMVETH_BUFF_OH 22 /* Overhead: 14 ethernet header + 8 opaque handle */
 #define IBMVETH_MAX_MTU 68
-- 
1.5.3.5.645.gbb47