Hello Emmanuel, I hope it's OK that I send you this directly. It's mostly for information in case the problem isn't yet known. I haven't debugged the issue properly. Please let me know if you want more details. I have been using my iwlwifi 0000:03:00.0: Detected Intel(R) Dual Band Wireless AC 7260, REV=0x144 module successfully with the 22.24.8.0 firware and the v3.14 driver ever since v3.14 was out (and before, if you count the latest -rc's). This has worked perfectly with all access points I've used, including a 802.11ac Linksys EA6700. But yesterday I got another 802.11ac access point, a Linksys WRT1900AC, and that gave me major problems. The problem is the same on both 2.4 and 5 GHz, so it doesn't look like it's really AC related: A few seconds after associating, the RX rate drops to minimum (1 or 6 MBit/s respectively), and the latency increases to high values. After a while frames are also being dropped, and the link becomes completely unusable. Googling a bit brought me this: https://bbs.archlinux.org/viewtopic.php?id=180558 and I thought that I might as well try reverting to the older firmware. And to my surprise: That made the problem go away. I realize that icmp echos don't necessarily tell the whole truth, but the same latency difference is noticable on e.g interactive ssh sessions as well. So I believe pinging illustrates the difference pretty well. The *only* thing changed between these sessions is the iwl firmware. Position, channel, driver, hardware is the same. This was captured on 2.4GHz. *** With "iwlwifi 0000:03:00.0: loaded firmware version 22.24.8.0 op_mode iwlmvm" *** : This is captured immedieately after association, showing the threshold where latency and rx rate goes bad: nemi:/usr/local/src/git# ping6 -c 30 fe80::215:17ff:fe1e:5e35%wlan0 PING fe80::215:17ff:fe1e:5e35%wlan0(fe80::215:17ff:fe1e:5e35) 56 data bytes 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=1 ttl=64 time=6.11 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=2 ttl=64 time=3.51 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=3 ttl=64 time=2.07 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=4 ttl=64 time=1.63 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=5 ttl=64 time=1.81 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=6 ttl=64 time=2.53 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=7 ttl=64 time=1.32 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=8 ttl=64 time=1.45 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=9 ttl=64 time=1.52 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=10 ttl=64 time=145 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=11 ttl=64 time=168 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=12 ttl=64 time=190 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=13 ttl=64 time=115 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=14 ttl=64 time=132 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=15 ttl=64 time=154 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=16 ttl=64 time=178 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=17 ttl=64 time=200 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=18 ttl=64 time=120 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=19 ttl=64 time=143 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=20 ttl=64 time=165 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=21 ttl=64 time=188 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=22 ttl=64 time=113 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=23 ttl=64 time=130 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=24 ttl=64 time=55.4 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=25 ttl=64 time=175 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=26 ttl=64 time=198 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=27 ttl=64 time=118 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=28 ttl=64 time=145 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=29 ttl=64 time=164 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=30 ttl=64 time=187 ms --- fe80::215:17ff:fe1e:5e35%wlan0 ping statistics --- 30 packets transmitted, 30 received, 0% packet loss, time 29044ms rtt min/avg/max/mdev = 1.326/107.209/200.702/74.548 ms nemi:/lib/firmware# iw wlan0 station dump;sleep 10; iw wlan0 station dump Station b4:75:0e:60:b7:e6 (on wlan0) inactive time: 136 ms rx bytes: 3842 rx packets: 26 tx bytes: 2775 tx packets: 21 tx retries: 0 tx failed: 0 signal: -54 [-57, -54] dBm signal avg: -56 [-59, -56] dBm tx bitrate: 5.5 MBit/s rx bitrate: 300.0 MBit/s MCS 15 40MHz short GI authorized: yes authenticated: yes preamble: long WMM/WME: yes MFP: no TDLS peer: no Station b4:75:0e:60:b7:e6 (on wlan0) inactive time: 132 ms rx bytes: 7630 rx packets: 64 tx bytes: 4891 tx packets: 39 tx retries: 1 tx failed: 0 signal: -75 [-75] dBm signal avg: -61 [-61] dBm tx bitrate: 12.0 MBit/s rx bitrate: 1.0 MBit/s authorized: yes authenticated: yes preamble: long WMM/WME: yes MFP: no TDLS peer: no A couple of minutes later: nemi:/usr/local/src/git# ping6 -c10 -W5 fe80::215:17ff:fe1e:5e35%wlan0 PING fe80::215:17ff:fe1e:5e35%wlan0(fe80::215:17ff:fe1e:5e35) 56 data bytes 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=1 ttl=64 time=112 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=2 ttl=64 time=133 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=3 ttl=64 time=156 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=4 ttl=64 time=178 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=6 ttl=64 time=123 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=7 ttl=64 time=144 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=9 ttl=64 time=185 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=10 ttl=64 time=207 ms --- fe80::215:17ff:fe1e:5e35%wlan0 ping statistics --- 10 packets transmitted, 8 received, 20% packet loss, time 9017ms rtt min/avg/max/mdev = 112.678/155.340/207.601/30.777 ms *** With "iwlwifi 0000:03:00.0: loaded firmware version 22.1.7.0 op_mode iwlmvm" *** : There is no degredation, and values similar to these are observed indefinitely: nemi:/usr/local/src/git# ping6 -c 20 fe80::215:17ff:fe1e:5e35%wlan0 PING fe80::215:17ff:fe1e:5e35%wlan0(fe80::215:17ff:fe1e:5e35) 56 data bytes 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=1 ttl=64 time=1.64 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=2 ttl=64 time=1.63 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=3 ttl=64 time=1.21 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=4 ttl=64 time=1.17 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=5 ttl=64 time=1.13 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=6 ttl=64 time=3.56 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=7 ttl=64 time=1.22 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=8 ttl=64 time=1.56 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=9 ttl=64 time=1.35 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=10 ttl=64 time=17.3 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=11 ttl=64 time=15.2 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=12 ttl=64 time=1.45 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=13 ttl=64 time=1.47 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=14 ttl=64 time=3.96 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=15 ttl=64 time=1.66 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=16 ttl=64 time=1.46 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=17 ttl=64 time=1.41 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=18 ttl=64 time=2.81 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=19 ttl=64 time=1.41 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=20 ttl=64 time=1.44 ms --- fe80::215:17ff:fe1e:5e35%wlan0 ping statistics --- 20 packets transmitted, 20 received, 0% packet loss, time 19029ms rtt min/avg/max/mdev = 1.137/3.210/17.317/4.440 ms nemi:/lib/firmware# iw wlan0 station dump Station b4:75:0e:60:b7:e6 (on wlan0) inactive time: 4324 ms rx bytes: 7077727 rx packets: 44372 tx bytes: 100337 tx packets: 1138 tx retries: 88 tx failed: 0 signal: -56 [-56] dBm signal avg: -56 [-56] dBm tx bitrate: 180.0 MBit/s MCS 12 40MHz short GI rx bitrate: 270.0 MBit/s MCS 15 40MHz authorized: yes authenticated: yes preamble: long WMM/WME: yes MFP: no TDLS peer: no *** with "firmware version 22.24.8.0", but connected to the EA6700, also on 2.4GHz *** : With more walls and a couple of floors inbetween, so latency and rates are expected to be a bit worse. But the link still works fine. There are no drops, and the RX rate stays well above minimum. Values similar to these are observed indefinitely: nemi:/usr/local/src/git# ping6 -c 30 fe80::215:17ff:fe1e:5e35%wlan0 PING fe80::215:17ff:fe1e:5e35%wlan0(fe80::215:17ff:fe1e:5e35) 56 data bytes 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=1 ttl=64 time=33.7 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=2 ttl=64 time=158 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=3 ttl=64 time=78.6 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=4 ttl=64 time=100 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=5 ttl=64 time=20.2 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=6 ttl=64 time=42.8 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=7 ttl=64 time=64.7 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=8 ttl=64 time=86.8 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=9 ttl=64 time=50.8 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=10 ttl=64 time=29.3 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=11 ttl=64 time=17.0 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=12 ttl=64 time=76.3 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=13 ttl=64 time=97.0 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=14 ttl=64 time=17.3 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=15 ttl=64 time=40.3 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=16 ttl=64 time=62.9 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=17 ttl=64 time=85.8 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=18 ttl=64 time=107 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=19 ttl=64 time=44.4 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=20 ttl=64 time=49.7 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=21 ttl=64 time=71.8 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=22 ttl=64 time=94.9 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=23 ttl=64 time=15.3 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=24 ttl=64 time=37.9 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=25 ttl=64 time=60.8 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=26 ttl=64 time=84.7 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=27 ttl=64 time=107 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=28 ttl=64 time=26.5 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=29 ttl=64 time=49.1 ms 64 bytes from fe80::215:17ff:fe1e:5e35: icmp_seq=30 ttl=64 time=72.7 ms --- fe80::215:17ff:fe1e:5e35%wlan0 ping statistics --- 30 packets transmitted, 30 received, 0% packet loss, time 29043ms rtt min/avg/max/mdev = 15.309/62.925/158.631/33.149 ms nemi:/lib/firmware# iw wlan0 station dump Station c8:d7:19:37:f5:94 (on wlan0) inactive time: 128 ms rx bytes: 50974 rx packets: 345 tx bytes: 14833 tx packets: 130 tx retries: 31 tx failed: 0 signal: -77 [-77] dBm signal avg: -77 [-77] dBm tx bitrate: 54.0 MBit/s rx bitrate: 39.0 MBit/s MCS 10 authorized: yes authenticated: yes preamble: long WMM/WME: yes MFP: no TDLS peer: no So what is the problem with the WRT1900AC and the 22.24.8.0 firmware? I realize that I probably should ask this question to Belkin instead, but the different behaviour based on iwl firmware versions puzzles me. And also the fact that none of my other clients seem to have similar problems with the WRT1900AC. Bjørn -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
