Bugzilla – Bug 1592
Speed drops when downloading at high speeds
Last modified: 2010-06-27 13:44:43
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lspci output: 06:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG Network Connection (rev 02) Using "iwl3945" driver (version 1.2.23) from John Linville's wireless git repository. I'm having some speed drops when I'm downloading at high speeds (downloading from usenet or copying data using samba). The download works fine for some minutes but then the speed drops from 800kb/s to ~100kb/s and the wireless connection starts to work very slow. I noticed that when this happens, the wireless transfer rate of my router (a Linksys WTR54GL) decreases to 1mbps (ONLY the transfer rate of the router). Also I tested that this happens with other routers so it's not problem of my router (with an atheros card the connection works correctly). I'm very near from it and I get very good signal. "dmesg" doesn't show anything strange (enabling debug mode doesn't help). Using ipw3945 driver everything works fine. PD: This problem used to happen with older versions (and it was much worse).
I can confirm this in Ubuntu there is a thread about that, some other people having problems with that issue too. https://bugs.launchpad.net/ubuntu/+source/linux-ubuntu-modules-2.6.2/+bug/176271 I have DSL connection 16Mbit/1Mbit. Upload is fine but I can't get a download rate higher then 50KB/s I'm using driver Version 1.1.17kds wich is included by default. Greetings Erik
I have this problem both with ipw3945 and iwl3945 (using a linksys wrt54gl, and wpa2). I don't have any problems with other wifi chipsets (atheros, broadcom, etc) This problem was reported in ubuntu bug tracker for ipw3945 : https://bugs.launchpad.net/ubuntu/+source/linux-ubuntu-modules-2.6.22/+bug/103210 And a workaround was given there, which works fine : sudo iwpriv eth1 set_mode 4 Is there a similar workaround for iwl3945? It's rather annoying, I get maybe the normal speed (~1MB/s) during 30 sec, then it drops at ~150kB/s, and it's stuck there, until I reload the iwl module.
(In reply to comment #2) > > This problem was reported in ubuntu bug tracker for ipw3945 : > https://bugs.launchpad.net/ubuntu/+source/linux-ubuntu-modules-2.6.22/+bug/103210 > I just found that there was an upstream bug report linked from there (also for ipw3945) : http://bughost.org/bugzilla/show_bug.cgi?id=1205
(In reply to comment #3) > I just found that there was an upstream bug report linked from there (also for > ipw3945) : > http://bughost.org/bugzilla/show_bug.cgi?id=1205 I don't know if this is equivalent to the "CCMP: replay detected" message mentioned in bug 1205 for ipw3945. But in iwl3945, when the performance drops, I get a big number of : iwl3945: I iwl3945_rx_reply_rx Dropping (dup)
Created an attachment (id=1354) [details] debug output when the performance is good That's the debug output I get after a fresh reload of the module, downloading a file at ~1 MB/s.
Created an attachment (id=1355) [details] debug output after the performance drop After ten seconds or something, the same download dropped to ~ 150 kB/s, and then it's stuck at this speed. Debug output I get during this phase, with many "iwl3945_rx_reply_rx Dropping (dup)" messages.
Is there any update for this? I have the same experience with the 1.2.26ks driver as well. I can provide logs if requested, I just want to see this resolved. TIA, Jeremy
I have the same problem on my Thinkpad T60. Before iwl3945 i had ipw3945 with the same problem. Only sometimes the command "iwpriv eth1 set_mode 4" fixed the problem. Now with iwl3945 sporadically my connection slow down again. Linksys WRT54G (hardware v2.2 with DD-WRT v24sp1) shows on statuspage a 5.5 mbps connection(!). Only a reconnect (eg. killswitch on laptop or wrt54g reboot) fix this. Kernel 2.6.26-gentoo with Intel(R) PRO/Wireless 3945ABG/BG Network Connection driver for Linux, 1.2.26ks
I tested on: ASUS WL500g IBM T60 FC9 32bit system 2.6.27-rc3 (iwl3945 1.2.26) using WPA-AES encryption to transfer a 50MByte file from T60 to server, speed drops from about 250KByte/s to 80KByte/s. The average speed is about 90KB/s that is 90*8Kb/s=720Kb/s.
I often streaming dvb-video over wlan with 600-800 kbyte/s. The strange thing is, sometimes the connection works fine for a hour - and sometimes it only works for few minutes till the connection break down. Then only a transfer with max 120kbyte/s is possible until a reconnect. Three days ago, i switched the WRT54G to G-only mode for testing. Up to now the problem hasn't occurred again.
Changed OS to ALL because this is reported on multiple distributions. I can confirm that switching the AP to G only "fixes" the issue. Although, my AP was on "mixed" before, shouldn't the driver select G if the AP offers it anyway? I am confused as to why when switching from Mixed to G only the problem disappears...maybe this is a clue?
(In reply to comment #11) > Changed OS to ALL because this is reported on multiple distributions. I can > confirm that switching the AP to G only "fixes" the issue. Although, my AP was > on "mixed" before, shouldn't the driver select G if the AP offers it anyway? I > am confused as to why when switching from Mixed to G only the problem > disappears...maybe this is a clue? > And if you set the AP to B only mode, the issue returns which leads me to believe that there is *something* wrong with the driver when it is in B mode. Also, leads me to wonder why this bug is hit when the AP offers B and G. Maybe the driver is selecting B over G and then hitting this problem again?
Same issue here (Thinkpad T61, Intel Wireless WiFi Link 3945ABG), except I am running my wireless router (Linksys WRT54GS firmware 4.70.6) in G-only mode and iwl3945 module still exhibits this slow and unreliable behavior. Confirmed on today's rev of iwl3945 compat-wireless-2.6-old v4.5-56-gcd7615b OS is Slackware 12.1 kernel 2.6.24.5-smp i686 Does not appear to be limited to operating in B.
*** Bug 1570 has been marked as a duplicate of this bug. ***
i'm using ubuntu Intrepid Ibex on both my XPS M1330 and my inspiron 9400. the 9400 got a 3945abg and the M1330 4965bgn card , they both have the same problem , after a short amount of time connection is capped at 130 kbit/s, under windows there is no problem so i believe it's not accesspoint related ( which one is an inventel and can't be put in g only mode ) but more likely driver related. Sometimes connection is just fine during 10 minutes and then fall. i try the qos_enable tips but it didn't work...
Created an attachment (id=1701) [details] Patch 1
Created an attachment (id=1702) [details] Patch 2
Created an attachment (id=1703) [details] Patch 3
Please try the above patches.
(In reply to comment #19) > Please try the above patches. > Hi, thanks. Can you let us know what kernel they will be accepted into? (haven't tested locally yet)
We haven't put it to upstream yet. We are expecting community's feedback before putting it in upstream
(In reply to comment #21) > We haven't put it to upstream yet. We are expecting community's feedback before > putting it in upstream > Alright. They don't apply to 2.6.27.7. What target are you going for?
patchs only applies to 3945 abg intel cards. But the bug is also affecting 4965 cards , could it be possible to let the bug as open ?
It can be applied to 2.6.28-rc5 wireless-testing (Linville's tree).
I apply the patch on the latest compat-wireless tree. compilation went fine and loading the module too. but after that speed is still capped at 130 kbit/s... dmesg is also flood with : iwl39456 : XXXY sta_stup_rate: 0XFFF
(In reply to comment #25) > I apply the patch on the latest compat-wireless tree. compilation went fine and > loading the module too. but after that speed is still capped at 130 kbit/s... > dmesg is also flood with : > iwl39456 : XXXY sta_stup_rate: 0XFFF > Same experience here. Guess the bug should be reopened.
Please check this commit. http://git.kernel.org/?p=linux/kernel/git/linville/wireless-testing.git;a=commit;h=2768672e7a3d1c427f436b0a91c942c2732dc320
Created an attachment (id=1744) [details] Please try out this patch
Clement please try above patch for 4965. Marking as tested patch exists.
I applied the above patch for 4965 to latest compat-wireless release. compialtion and installation were fine. So far i'm testing it it seems to handle an intense traffic, i will do more test and report if it really solve the problem. I also check the commit for 3045 on john linville's tree but i don't know if it has been incorporated in compat-wireless, anyway i install latest compat-wireless ( for the 3945 card ) too but speed is still capped...
(4965) I spoke too fast, after a few minutes connection fell...capped at 130 kbits
What is the date of compat version.
that was the latest version. According to linux-wireless website they update compat-wireless really frequently with John Linville's tree. After another test i didn't have the problem with a abgn access point. but at home with my bg access,point I have the issue.
For Home ap ,what band are you working on b or g or mixed. What is the signal quality you can see?
Created an attachment (id=1762) [details] iwconfig result when attached to the AP
My home ap is bg mixed encrypted with 128bit key. See the iwconfig result attached
As the original reporter of bug 1205 I can confirm it's still an issue for me. I'm pleased that this is now being looked at by those a little more technically capable than me of testing kernel modules and building new modules. For what it's worth, I got this bug irrespective of b/g and with different model AP's and irrespective of encryption. It's certainly a driver issue as I don't get the issue in Windows, or by using the Windows driver through ndiswrapper. I always found that if the signal strength was really strong (i.e. next to AP) then the bug would not appear as quickly, however you could replicate the bug very quickly by taking the laptop to the limit of the signal, then coming back to full signal. The transfer rate would drop immediately in this case. Here's hoping for a fix. It'll save me some cash on a new wlan card for my laptop! Thanks Chris(In reply to comment #36) > My home ap is bg mixed encrypted with 128bit key. See the iwconfig result > attached >
I also have this problem. The problem rarely (if ever) occurs if machine has not been resumed from suspend-to-ram. I can not say with certainty if it ever occurs on a "cold-booted" machine as I've only noticed the connection between suspend-to-ram and this bug couple of weeks ago. If speed drops reloading driver helps about 80% of the time, and improved speed persists anywhere from 10 minutes to several hours. Running 3945 and the iwlwifi driver from 2.6.28 (vanilla) kernel (.26 and .27 both had the problem, don't recall about earlier versions).
I have the same problem, but I hope my setup could provide additional information as I have two two laptops, dell inspiron E1705 and lenovo 161P, and Inspiron is the one having a problem while Lenovo is always problem-free. Inspiron worked fine with the good old ipw3945 driver, I wish I could still use that! lspci output from Lenovo: Network controller [0280]: Intel Corporation PRO/Wireless 3945ABG Network Connection [8086:4227] (rev 02) lspci output from has: Network controller [0280]: Intel Corporation PRO/Wireless 3945ABG Network Connection [8086:4222] (rev 02) Inspiron has problems in both cleartext and encrypted configurations. Lenovo works fine in both configurations. I have also tried two different access points. Access points make no difference. Lenovo is running some 2.6.26 gentoo kernel w/o any additional drivers, patches, etc. I have tried a variety of different kernels and driver versions on the Inspiron and right now it is running 2.6.28-tuxonice-r1 kernel with compat-wireless-2009-01-30 drivers. With earlier code I was also experiencing huge packet loss. Right now packet loss seems to be ok but the download speeds are still terrible. I have copied over kernel, initrd and modules from Lenovo to Inspiron hoping that somehow 2.6.26 gentoo kernel makes it work, but Inspiron still has the same problem even when it runs exactly the same code as my problem-free Lenovo. So either there is some other hardware on the Inspiron that is causing the problem or the card itself is different enough to cause the problem. I know both say "rev 02" but 4227 is different from 4222 so i'm assuming these cards are different revs. I have not tried moving the cards between the laptops yet, but I could try that if someone could use that data point. I'd like to help out (run tests, collect debug outputs, try patches, etc) if there is anyone ready to work with me on this.
Adding to my previous comment. Unfortunately it looks like lenovo has the 3945 built it, so I won't be able to swap cards between inspiron and lenovo, but i could still load debug code on both , and/or collect debug to try to figure what the difference is.
I have the same problem here. Speed drops from ~700K/s to ~150K/s and stays there. Sometimes reloading the module helps, sometimes not.
Please try the latest kernel. Patch mentioned in comments 16,17,18 are already applied to latest kernel.
(In reply to comment #42) > Please try the latest kernel. Patch mentioned in comments 16,17,18 are already > applied to latest kernel. > Abhigeet, Could you specify the exact version to try? i.e. branch, etc? Are those patches also in compat-wireless? I tried the latest compat-wireless (2009-02-10) and it does not seem to make any difference.
Compat one has the above patch already. I am not able to reproduce this problem so Can you do one more test between lenovo and inspiron? Can you tell me the signal strength you are getting from same ap or you can post iwconfig o/p after associating with AP.
It looks like I got bad results last night because I unloaded old driver and loaded the new without a reboot in between. I just booted the laptop up tonight and performance looks really good! Thanks!!!
Marking it as fixed after user reported success.
(In reply to comment #46) > Marking it as fixed after user reported success. > So, it is still not clear to me what kernel versions have this patch. I tried the patches applied to 2.6.28-rc5 after Comment #16 with no results.
Mark it as Verified. Please reopen it if you still see this issue with latest driver.
The bug still occurs in the latest stable kernel (2.6.28.7).
For the other victims of this bug: If you reload the module fast enough, downloads won't be interrupted. I wrote this little script to "fix" the bug: /etc/rc.d/wpa stop /etc/rc.d/net stop rmmod iwl3945 sleep 2 modprobe iwl3945 sleep 2 /etc/rc.d/net start /etc/rc.d/wpa start wpa start/stop is my starts/stops wpa_supplicant, you'll need to change that for your system. net start/stop brings the network interface up/down and assigns/kills IPs and routes. Run this when the speed drops and you'll have full speed again for some time, and 90% of the runnings downloads are not interrupted. :)
Sorry for spamming here. After testing the new kernel for a while I think the problem got even worse. The speed drops almost instantly after starting a download. After reloading the module, the normal speed stays only for 10-20 seconds, then it drops to about 150K/s. Sometimes it even drops to a few bytes per second. Is there anything I can do to help you fixing this soon? This bug makes the card pretty much useless.
What's the output of iwconfig after the speed drops?
wlan0 IEEE 802.11abg ESSID:"XXXXX" Mode:Managed Frequency:2.412 GHz Access Point: XX:XX:XX:XX:XX:XX Bit Rate=54 Mb/s Tx-Power=15 dBm Retry min limit:7 RTS thr:off Fragment thr=2352 B Encryption key:XXXXX Security mode:open Power Management:off Link Quality=93/100 Signal level:-36 dBm Noise level=-127 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0
Jonas, Can you send me the log using debug=0x40840002?
Created an attachment (id=1852) [details] Debug log when speed drops The speed drop happened around 21:35.
Created an attachment (id=1859) [details] Rate scaling patch Can you check with attached patch and report your finding?
For which kernel version is the patch? It doesn't apply to 2.6.28.7: Hunk #1 FAILED at 298. Hunk #2 succeeded at 269 with fuzz 2 (offset -75 lines). Hunk #3 FAILED at 404. Hunk #4 FAILED at 493. Hunk #5 succeeded at 658 (offset 75 lines). Hunk #6 succeeded at 518 with fuzz 1 (offset -76 lines). Hunk #7 succeeded at 677 (offset 75 lines). Hunk #8 succeeded at 539 with fuzz 1 (offset -76 lines). Hunk #9 FAILED at 647. Hunk #10 succeeded at 793 with fuzz 2 (offset 53 lines). Hunk #11 succeeded at 676 (offset -75 lines). Hunk #12 FAILED at 702. Hunk #13 FAILED at 724. Hunk #14 FAILED at 737.
It can be applied to 2.6.29-rc6-iwlwifi. You can download the comapct package from here and apply the patch http://wireless.kernel.org/download/compat-wireless-2.6/
The patch applies fine to the compat package and the drivers compile fine too. However, I can't load the iwl3945 module: $ modprobe iwl3945 FATAL: Error inserting iwl3945 (/lib/modules/2.6.28.7/updates/drivers/net/wireless/iwlwifi/iwl3945.ko): Unknown symbol in module, or unknown parameter (see dmesg) dmesg shows a ton of "undefined symbol: ..." messages.
This is not a driver problem but something messed up while building the driver. Check this. http://wireless.kernel.org/en/users/Download#Archiveofcompat-wireless-2.6tarballs
I've read the README before and that's exactly how I did it. Is there anything else the could go wrong?
I am not sure about it. But a clean build will help. Let me know how it goes. You can apply this patch on top of rate scaling patch. http://www.intellinuxwireless.org/bugzilla/attachment.cgi?id=1869
Please check new compact wireless package. Marking this bug as fixed. If you see this issue open the bug again.
Mark as verified. Please reopen if it still exists
Sorry for the lack of feedback. I have mostly been away from my wrt54gl during 1,5 year. I even changed laptop in between but it still uses iwl3945. And now I am back full time and this router... and the issue is back with it :P I am now on vanilla 2.6.32 64bit, but the behavior is still exactly the same : a download will start at a good 800 kB/s speed for less than one minute, then drops to 150 kB/s with no way back.. until next reload of iwl3945. I am fully available to provide more information (I suppose a dmesg would be a start but which debug level?), test new code (should I try a wireless git tree?), new patches, etc. # lspci -v 0b:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev 02) Subsystem: Intel Corporation Device 1021 Flags: bus master, fast devsel, latency 0, IRQ 30 Memory at f1eff000 (32-bit, non-prefetchable) [size=4K] Capabilities: [c8] Power Management version 2 Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+ Capabilities: [e0] Express Legacy Endpoint, MSI 00 Capabilities: [100] Advanced Error Reporting Capabilities: [140] Device Serial Number 00-1f-3c-ff-ff-cc-f5-e9 Kernel driver in use: iwl3945 Kernel modules: iwl3945 # iwconfig wlan0 wlan0 IEEE 802.11abg ESSID:"maison" Mode:Managed Frequency:2.462 GHz Access Point: 00:18:F8:F1:BD:D9 Bit Rate=48 Mb/s Tx-Power=15 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:on Link Quality=36/70 Signal level=-74 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 # iwlist wlan0 scan wlan0 Scan completed : Cell 01 - Address: 00:18:F8:F1:BD:D9 Channel:11 Frequency:2.462 GHz (Channel 11) Quality=35/70 Signal level=-75 dBm Encryption key:on ESSID:"maison" Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s 24 Mb/s; 36 Mb/s; 54 Mb/s Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s Mode:Master Extra:tsf=000001dd67e9968c Extra: Last beacon: 87ms ago IE: Unknown: 00066D6169736F6E IE: Unknown: 010882848B962430486C IE: Unknown: 03010B IE: Unknown: 2A0100 IE: Unknown: 2F0100 IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : CCMP Pairwise Ciphers (1) : CCMP Authentication Suites (1) : PSK IE: Unknown: 32040C121860 IE: Unknown: DD090010180203F0000000 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00
Does it only happen with WRT54GL? We have another bug opened for WRT54GL.(Bug no 1932).Please mark this as duplicate.
*** This bug has been marked as a duplicate of bug 1932 ***
Mark as Verified.
I've got an affected 3945ABG. I'm sitting right next to the router. Windows: 1536 KB/s downstream Linux: 150 KB/s downstream I've had this problem with both a Netgear WNDR3300 and a Linksys WRT54G v5. I can't deal with this garbage.