Bug? Kernels 2.6.2x drops TCP packets over wireless (independent of card used)

From: Marcin Koziej
Date: Thu Feb 07 2008 - 04:06:17 EST


Hello, I have problem with wireless network connectivity;
I have tested this on two wireless cards, both giving same results:
These are:
1) 02:00.0 Ethernet controller: Atheros Communications, Inc. AR5212 802.11abg NIC (rev 01)
working under madwifi-0.9.3.3
2) 00:0a.0 Ethernet controller: Linksys, A Division of Cisco Systems [AirConn] INPROCOMM IPN 2220 Wireless LAN Adapter (rev 01)
working under ndiswrapper on neti2220 driver

On kernel 2.6.19 both cards are working fine (with same network configuration)

Problems arise on kernels 2.6.2x, information below is from 2.6.23, but 2.6.24-rc8-git7 also was tested:
Both cards can associate with ap, and get TCP/IP configuration from the router.
Both cards can ping the router (0% packet loss), resolve hostnames using DNS (suggesting UDP is working fine).
However, when any kind of TCP connection is made, it hangs after initial handshake and maybe some ammount of data interchanged. This is checked by tcpdump provided below.

This happens every time to all tcp connections.

Example with Atheros card:
ath0 IEEE 802.11g ESSID:"hotspot" Nickname:""
Mode:Managed Frequency:2.462 GHz Access Point: 00:60:B3:6C:A1:2E
Bit Rate:11 Mb/s Tx-Power:17 dBm Sensitivity=1/1
Retry:off RTS thr:off Fragment thr:off
Power Management:off
Link Quality=19/70 Signal level=-77 dBm Noise level=-96 dBm
Rx invalid nwid:43882 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0


# ftp ftp.icm.edu.pl
Connected to ftp.icm.edu.pl (193.219.28.140).
220-
(hangs)

The packet dump is:
23:56:08.807674 IP 192.168.1.2.51909 > sunsite2.icm.edu.pl.ftp: S
980196671:980196671(0) win 5840 <mss 1460,sackOK,timestamp 1971553
0,nop,wscale 5>
0x0000: 4500 003c 885e 4000 4006 124c c0a8 0102 E..<.^@.@..L....
0x0010: c1db 1c8c cac5 0015 3a6c 9d3f 0000 0000 ........:l.?....
0x0020: a002 16d0 d91a 0000 0204 05b4 0402 080a ................
0x0030: 001e 1561 0000 0000 0103 0305 ...a........
23:56:08.821639 IP sunsite2.icm.edu.pl.ftp > 192.168.1.2.51909: S
2723526584:2723526584(0) ack 980196672 win 5792 <mss 1460,sackOK,timestamp
983901832 1971553,nop,wscale 7>
0x0000: 4500 003c 0000 4000 3c06 9eaa c1db 1c8c E..<..@.<.......
0x0010: c0a8 0102 0015 cac5 a255 b7b8 3a6c 9d40 .........U..:l.@
0x0020: a012 16a0 1dfc 0000 0204 05b4 0402 080a ................
0x0030: 3aa5 2688 001e 1561 0103 0307 :.&....a....
23:56:08.821685 IP 192.168.1.2.51909 > sunsite2.icm.edu.pl.ftp: . ack 1 win 183
<nop,nop,timestamp 1971567 983901832>
0x0000: 4500 0034 885f 4000 4006 1253 c0a8 0102 E..4._@.@..S....
0x0010: c1db 1c8c cac5 0015 3a6c 9d40 a255 b7b9 ........:l.@.U..
0x0020: 8010 00b7 62a3 0000 0101 080a 001e 156f ....b..........o
0x0030: 3aa5 2688 :.&.
23:56:08.842801 IP sunsite2.icm.edu.pl.ftp > 192.168.1.2.51909: P 1:7(6) ack 1
win 46 <nop,nop,timestamp 983901837 1971567>
0x0000: 4510 003a 9135 4000 3c06 0d67 c1db 1c8c E..:.5@.<..g....
0x0010: c0a8 0102 0015 cac5 a255 b7b9 3a6c 9d40 .........U..:l.@
0x0020: 8018 002e f3af 0000 0101 080a 3aa5 268d ............:.&.
0x0030: 001e 156f 3232 302d 0d0a ...o220-..
23:56:08.843069 IP 192.168.1.2.51909 > sunsite2.icm.edu.pl.ftp: . ack 7 win 183
<nop,nop,timestamp 1971588 983901837>
0x0000: 4510 0034 8860 4000 4006 1242 c0a8 0102 E..4.`@.@..B....
0x0010: c1db 1c8c cac5 0015 3a6c 9d40 a255 b7bf ........:l.@.U..
0x0020: 8010 00b7 6283 0000 0101 080a 001e 1584 ....b...........
0x0030: 3aa5 268d :.&.
23:56:31.920327 IP 192.168.1.2.51909 > sunsite2.icm.edu.pl.ftp: F 1:1(0) ack 7
win 183 <nop,nop,timestamp 1994676 983901837>
0x0000: 4510 0034 8861 4000 4006 1241 c0a8 0102 E..4.a@.@..A....
0x0010: c1db 1c8c cac5 0015 3a6c 9d40 a255 b7bf ........:l.@.U..
0x0020: 8011 00b7 0852 0000 0101 080a 001e 6fb4 .....R........o.
0x0030: 3aa5 268d :.&.
23:56:31.935145 IP sunsite2.icm.edu.pl.ftp > 192.168.1.2.51909: . ack 2 win 46
<nop,nop,timestamp 983907613 1994676>
0x0000: 4510 0034 913d 4000 3c06 0d65 c1db 1c8c E..4.=@.<..e....
0x0010: c0a8 0102 0015 cac5 a255 b8e5 3a6c 9d41 .........U..:l.A
0x0020: 8010 002e f124 0000 0101 080a 3aa5 3d1d .....$......:.=.
0x0030: 001e 6fb4 ..o.
(no more packets)


System:
I am using Atheros Communications, Inc. AR5212 802.11abg NIC PCMCIA card.
Computer is notebook, Acer Aspire 1520.

I use vanilla kernel:
Linux 2.6.23 #1 Sat Jan 12 12:07:39 CET 2008 i686 AMD Athlon(tm) 64 Processor
3700+ AuthenticAMD GNU/Linux
and madwifi driver ath_pci 0.9.4.5 (0.9.3.3)
kernel options: irqpoll (without irqpoll system doesn't detect pcmcia cards).

Device detection:
ath_hal: module license 'Proprietary' taints kernel.
ath_hal: 0.9.18.0 (AR5210, AR5211, AR5212, RF5111, RF5112, RF2413, RF5413)
ath_pci: 0.9.4.5 (0.9.3.3)
ath_rate_sample: 1.2 (0.9.3.3)
wifi0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
wifi0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps
36Mbps 48Mbps 54Mbps
wifi0: turboG rates: 6Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
wifi0: H/W encryption support: WEP AES AES_CCM TKIP
wifi0: mac 5.9 phy 4.3 radio 4.6
wifi0: Use hw queue 1 for WME_AC_BE traffic
wifi0: Use hw queue 0 for WME_AC_BK traffic
wifi0: Use hw queue 2 for WME_AC_VI traffic
wifi0: Use hw queue 3 for WME_AC_VO traffic
wifi0: Use hw queue 8 for CAB traffic
wifi0: Use hw queue 9 for beacons
wifi0: Atheros 5212: mem=0x34000000, irq=11

On the same irq are:
ehci_hcd:usb1
eth0
uhci_hcd:usb4
wifi%d
yenta

Please CC me in reply, since I'm not subscribed to the list.
If more debug information is needed please don't hesitate to ask.

Best regards,
Marcin Koziej

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