From: Ivan Vecera <ivecera@redhat.com>
Date: Fri, 13 Mar 2009 16:15:36 +0100
Subject: [net] tulip: MTU problems with 802.1q tagged frames
Message-id: 1236957336-11030-1-git-send-email-ivecera@redhat.com
O-Subject: [RHEL5.4 PATCH] tulip: Fix for MTU problems with 802.1q tagged frames
Bugzilla: 484796
RH-Acked-by: Andy Gospodarek <gospo@redhat.com>
RH-Acked-by: Michal Schmidt <mschmidt@redhat.com>
RH-Acked-by: Kyle McMartin <kyle@redhat.com>
RH-Acked-by: David Miller <davem@redhat.com>
BZs:
#484796 - tulip driver MTU problems when using dot1q vlans
Description:
This patch fixes MTU problem, which occurs when using 802.1q VLANs.
Received frames lenght should be up to 1518 bytes instead of 1514.
Test status:
Tested successfully.
Upstream status:
http://www.spinics.net/lists/netdev/msg90695.html
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
diff --git a/drivers/net/tulip/interrupt.c b/drivers/net/tulip/interrupt.c
index 99ccf2e..bf7c90e 100644
--- a/drivers/net/tulip/interrupt.c
+++ b/drivers/net/tulip/interrupt.c
@@ -143,6 +143,7 @@ int tulip_poll(struct net_device *dev, int *budget)
/* If we own the next entry, it is a new packet. Send it up. */
while ( ! (tp->rx_ring[entry].status & cpu_to_le32(DescOwned))) {
s32 status = le32_to_cpu(tp->rx_ring[entry].status);
+ short pkt_len;
if (tp->dirty_rx + RX_RING_SIZE == tp->cur_rx)
@@ -154,8 +155,28 @@ int tulip_poll(struct net_device *dev, int *budget)
if (--rx_work_limit < 0)
goto not_done;
- if ((status & 0x38008300) != 0x0300) {
- if ((status & 0x38000300) != 0x0300) {
+ /*
+ * Omit the four octet CRC from the length.
+ * (May not be considered valid until we have
+ * checked status for RxLengthOver2047 bits)
+ */
+ pkt_len = ((status >> 16) & 0x7ff) - 4;
+
+ /*
+ * Maximum pkt_len is 1518 (1514 + vlan header)
+ * Anything higher than this is always invalid
+ * regardless of RxLengthOver2047 bits
+ */
+
+ if ((status & (RxLengthOver2047 |
+ RxDescCRCError |
+ RxDescCollisionSeen |
+ RxDescRunt |
+ RxDescDescErr |
+ RxWholePkt)) != RxWholePkt
+ || pkt_len > 1518) {
+ if ((status & (RxLengthOver2047 |
+ RxWholePkt)) != RxWholePkt) {
/* Ingore earlier buffers. */
if ((status & 0xffff) != 0x7fff) {
if (tulip_debug > 1)
@@ -164,30 +185,23 @@ int tulip_poll(struct net_device *dev, int *budget)
dev->name, status);
tp->stats.rx_length_errors++;
}
- } else if (status & RxDescFatalErr) {
+ } else {
/* There was a fatal error. */
if (tulip_debug > 2)
printk(KERN_DEBUG "%s: Receive error, Rx status %8.8x.\n",
dev->name, status);
tp->stats.rx_errors++; /* end of a packet.*/
- if (status & 0x0890) tp->stats.rx_length_errors++;
+ if (pkt_len > 1518 ||
+ (status & RxDescRunt))
+ tp->stats.rx_length_errors++;
+
if (status & 0x0004) tp->stats.rx_frame_errors++;
if (status & 0x0002) tp->stats.rx_crc_errors++;
if (status & 0x0001) tp->stats.rx_fifo_errors++;
}
} else {
- /* Omit the four octet CRC from the length. */
- short pkt_len = ((status >> 16) & 0x7ff) - 4;
struct sk_buff *skb;
-#ifndef final_version
- if (pkt_len > 1518) {
- printk(KERN_WARNING "%s: Bogus packet size of %d (%#x).\n",
- dev->name, pkt_len, pkt_len);
- pkt_len = 1518;
- tp->stats.rx_length_errors++;
- }
-#endif
/* Check if the packet is long enough to accept without copying
to a minimally-sized skbuff. */
if (pkt_len < tulip_rx_copybreak
@@ -371,14 +385,35 @@ static int tulip_rx(struct net_device *dev)
/* If we own the next entry, it is a new packet. Send it up. */
while ( ! (tp->rx_ring[entry].status & cpu_to_le32(DescOwned))) {
s32 status = le32_to_cpu(tp->rx_ring[entry].status);
+ short pkt_len;
if (tulip_debug > 5)
printk(KERN_DEBUG "%s: In tulip_rx(), entry %d %8.8x.\n",
dev->name, entry, status);
if (--rx_work_limit < 0)
break;
- if ((status & 0x38008300) != 0x0300) {
- if ((status & 0x38000300) != 0x0300) {
+
+ /*
+ Omit the four octet CRC from the length.
+ (May not be considered valid until we have
+ checked status for RxLengthOver2047 bits)
+ */
+ pkt_len = ((status >> 16) & 0x7ff) - 4;
+ /*
+ Maximum pkt_len is 1518 (1514 + vlan header)
+ Anything higher than this is always invalid
+ regardless of RxLengthOver2047 bits
+ */
+
+ if ((status & (RxLengthOver2047 |
+ RxDescCRCError |
+ RxDescCollisionSeen |
+ RxDescRunt |
+ RxDescDescErr |
+ RxWholePkt)) != RxWholePkt
+ || pkt_len > 1518) {
+ if ((status & (RxLengthOver2047 |
+ RxWholePkt)) != RxWholePkt) {
/* Ingore earlier buffers. */
if ((status & 0xffff) != 0x7fff) {
if (tulip_debug > 1)
@@ -387,31 +422,22 @@ static int tulip_rx(struct net_device *dev)
dev->name, status);
tp->stats.rx_length_errors++;
}
- } else if (status & RxDescFatalErr) {
+ } else {
/* There was a fatal error. */
if (tulip_debug > 2)
printk(KERN_DEBUG "%s: Receive error, Rx status %8.8x.\n",
dev->name, status);
tp->stats.rx_errors++; /* end of a packet.*/
- if (status & 0x0890) tp->stats.rx_length_errors++;
+ if (pkt_len > 1518 ||
+ (status & RxDescRunt))
+ tp->stats.rx_length_errors++;
if (status & 0x0004) tp->stats.rx_frame_errors++;
if (status & 0x0002) tp->stats.rx_crc_errors++;
if (status & 0x0001) tp->stats.rx_fifo_errors++;
}
} else {
- /* Omit the four octet CRC from the length. */
- short pkt_len = ((status >> 16) & 0x7ff) - 4;
struct sk_buff *skb;
-#ifndef final_version
- if (pkt_len > 1518) {
- printk(KERN_WARNING "%s: Bogus packet size of %d (%#x).\n",
- dev->name, pkt_len, pkt_len);
- pkt_len = 1518;
- tp->stats.rx_length_errors++;
- }
-#endif
-
/* Check if the packet is long enough to accept without copying
to a minimally-sized skbuff. */
if (pkt_len < tulip_rx_copybreak
diff --git a/drivers/net/tulip/tulip.h b/drivers/net/tulip/tulip.h
index 3bcfbf3..8ec4b5d 100644
--- a/drivers/net/tulip/tulip.h
+++ b/drivers/net/tulip/tulip.h
@@ -192,9 +192,44 @@ struct tulip_tx_desc {
enum desc_status_bits {
- DescOwned = 0x80000000,
- RxDescFatalErr = 0x8000,
- RxWholePkt = 0x0300,
+ DescOwned = 0x80000000,
+ DescWholePkt = 0x60000000,
+ DescEndPkt = 0x40000000,
+ DescStartPkt = 0x20000000,
+ DescEndRing = 0x02000000,
+ DescUseLink = 0x01000000,
+
+ /*
+ * Error summary flag is logical or of 'CRC Error', 'Collision Seen',
+ * 'Frame Too Long', 'Runt' and 'Descriptor Error' flags generated
+ * within tulip chip.
+ */
+ RxDescErrorSummary = 0x8000,
+ RxDescCRCError = 0x0002,
+ RxDescCollisionSeen = 0x0040,
+
+ /*
+ * 'Frame Too Long' flag is set if packet length including CRC exceeds
+ * 1518. However, a full sized VLAN tagged frame is 1522 bytes
+ * including CRC.
+ *
+ * The tulip chip does not block oversized frames, and if this flag is
+ * set on a receive descriptor it does not indicate the frame has been
+ * truncated. The receive descriptor also includes the actual length.
+ * Therefore we can safety ignore this flag and check the length
+ * ourselves.
+ */
+ RxDescFrameTooLong = 0x0080,
+ RxDescRunt = 0x0800,
+ RxDescDescErr = 0x4000,
+ RxWholePkt = 0x00000300,
+ /*
+ * Top three bits of 14 bit frame length (status bits 27-29) should
+ * never be set as that would make frame over 2047 bytes. The Receive
+ * Watchdog flag (bit 4) may indicate the length is over 2048 and the
+ * length field is invalid.
+ */
+ RxLengthOver2047 = 0x38000010
};
distrib
>
Scientific%20Linux
>
5x
>
x86_64
>
by-pkgid
>
fc11cd6e1c513a17304da94a5390f3cd
>
files
>
2499
