Bug 8279

Summary:	PS3: ipv6 causes ethernet hang
Product:	Platform Specific/Hardware	Reporter:	Geoff Levand (geoffrey.levand)
Component:	PS3	Assignee:	Olaf Kirch (okir)
Status:	RESOLVED CODE_FIX
Severity:	normal	CC:	dwmw2, okir
Priority:	P2
Hardware:	i386
OS:	Linux
Kernel Version:	2.6.21-rc5-ps3-linux-dev-g07b2d645	Subsystem:
Regression:	---	Bisected commit-id:

Description Geoff Levand 2007-03-28 17:03:25 UTC

Gelic ether driver seems to hang when using ipv6.

<6>NETDEV WATCHDOG: eth0: transmit timed out
Timed out. Restarting...
 -> gelic_net_open:1386
<5>nfs: server 192.168.1.10 OK

Steps to reproduce:

1) On the PS3 'ip -6 addr add fec0::1/64 dev eth0'.

2) On another machine "ip -6 addr add fec0::2/64 dev eth0".
3) On the other machine "ssh fec0::1"

Comment 1 David Woodhouse 2007-03-29 08:45:03 UTC

Note that icmp6 and udp6 seem to work just fine -- it's just tcp6 which kills
it. A checksum problem, perhaps?

Comment 2 Olaf Kirch 2007-04-11 04:51:30 UTC

Likely.

I don't know if this is the latest driver, but the patch I found claims that
the device supports arbitrary checksumming (NETIF_F_HW_CSUM) but really just
supports NETIF_F_IP_CSUM:

+static void
+gelic_net_set_txdescr_cmdstat(struct gelic_net_descr *descr,
+			       struct sk_buff *skb, int middle)
+{
+	uint32_t nocs, tcpcs, udpcs;
+
+	if (middle) {
+		nocs =  GELIC_NET_DMAC_CMDSTAT_NOCS;
+		tcpcs = GELIC_NET_DMAC_CMDSTAT_TCPCS;
+		udpcs = GELIC_NET_DMAC_CMDSTAT_UDPCS;
+	}else {
+		nocs =  GELIC_NET_DMAC_CMDSTAT_NOCS  
+			| GELIC_NET_DMAC_CMDSTAT_END_FRAME;
+		tcpcs = GELIC_NET_DMAC_CMDSTAT_TCPCS 
+			| GELIC_NET_DMAC_CMDSTAT_END_FRAME;
+		udpcs = GELIC_NET_DMAC_CMDSTAT_UDPCS 
+			| GELIC_NET_DMAC_CMDSTAT_END_FRAME;
+	}
+
+	if (skb->ip_summed != CHECKSUM_HW) {
+		descr->dmac_cmd_status = nocs;
+	} else {
+		/* is packet ip?
+		 * if yes: tcp? udp? */
+		if (skb->protocol == htons(ETH_P_IP)) {
+			if (skb->nh.iph->protocol == IPPROTO_TCP) {
+				descr->dmac_cmd_status = tcpcs;
+			} else if (skb->nh.iph->protocol == IPPROTO_UDP) {
+				descr->dmac_cmd_status = udpcs;
+			} else { /* the stack should checksum non-tcp and 
non-udp
+				    packets on his own: NETIF_F_IP_CSUM */
+				descr->dmac_cmd_status = nocs;
+			}
+		}
+	}
+}


This means if tx checksums are enabled, and a non-IP packet is sent,
descr->dmac_cmd_status will potentially contain garbage.

Simple fix: s/NETIF_F_HW_CSUM/NETIF_F_IP_CSUM/

If the card indeed supports any kind of checksum, gelic_net_set_txdescr_cmdstat
needs to be fixed to do the right thing.

Comment 3 David Woodhouse 2007-04-13 06:19:39 UTC

 s/NETIF_F_HW_CSUM/NETIF_F_IP_CSUM/ works fine here; thanks.

Comment 4 Olaf Kirch 2007-04-13 06:51:43 UTC

Okay, whom do I talk to to get this patch included? The driver isn't in
mainline.

Comment 5 David Woodhouse 2007-04-13 06:54:24 UTC

They're aware of this issue already but for future reference I suppose
cbe-oss-dev@ozlabs.org

Comment 6 Olaf Kirch 2007-04-13 13:26:57 UTC

Patch submitted to Geoff + cbe-oss-dev@ozlabs.org
Closing as fixed