[arch-general] Wifi disconnects every few minutes

[Fulcrum]

Hi everybody,

I have an Alfa AWUS036H USB Wifi adapter (Ralink Technology, Corp. 
RT2870/RT3070 Wireless Adapter). It's using rt2800usb driver. I use 
netctl to connect to wifi.Here is my netctl profile:

Description='Mine'
Interface=wlp0s18f2u4
Connection=wireless
Security=none
ESSID=ncepu-student
IP=static
Address='10.110.7.7/24'
Gateway='10.110.7.254'
DNS=("8.8.8.8";"8.8.4.4")

The problem is that 'ip addr show' says that I'm still connected to my 
wifi AP. I can see my IP and everything but I can't access internet. I 
can't even ping google or any other server. When I try to curl a local 
LAN web server, it says 'there is no route to xxx.xxx.xxx.xxx', where 
xxx.xxx.xxx.xxx is my local router. So  I have to disconnect and 
reconnect every few minutes to use internet.

Here are ping results to a local server (while still connected to wifi, 
as per 'ip addr'):

PING yyy.yyy.yyy.yyy (yyy.yyy.yyy.yyy) 56(84) bytes of data.
 From 10.110.7.7 icmp_seq=1 Destination Host Unreachable
 From 10.110.7.7 icmp_seq=2 Destination Host Unreachable
 From 10.110.7.7 icmp_seq=3 Destination Host Unreachable
 From 10.110.7.7 icmp_seq=4 Destination Host Unreachable
 From 10.110.7.7 icmp_seq=5 Destination Host Unreachable
 From 10.110.7.7 icmp_seq=6 Destination Host Unreachable
^C
--- yyy,yyy.yyy.yyy ping statistics ---
6 packets transmitted, 0 received, +6 errors, 100% packet loss, time 5008ms

Where yyy.yyy.yyy.yyy is a server that is always available to all PCs 
connected to local LAN or wifi.

I read somewhere that netctl and dhcp don't work well together so I 
changed DHCP to static IP*. I even tried changing the wifi access points 
(There are multiple APs around me). In all cases, I am able to connect 
to the AP and use internet, but only for a few minutes.

For debugging, I removed the usb cable, and reattached the wifi 
adapter.Here are some entries from dmesg showing the plugging in of the 
adapter and subsequent connection trials. Note that I disconnected and 
reconnected the AP around [21713.142829].

[20962.199042] usb 6-4: new high-speed USB device number 3 using ehci-pci
[20962.455180] usb 6-4: reset high-speed USB device number 3 using ehci-pci
[20962.595540] ieee80211 phy1: rt2x00_set_rt: Info - RT chipset 3070, 
rev 0201 detected
[20962.651113] ieee80211 phy1: rt2x00_set_rf: Info - RF chipset 0005 
detected
[20962.651670] ieee80211 phy1: Selected rate control algorithm 'minstrel_ht'
[20962.685678] rt2800usb 6-4:1.0 wlp0s18f2u4: renamed from wlan0
[20987.396145] ieee80211 phy1: rt2x00lib_request_firmware: Info - 
Loading firmware file 'rt2870.bin'
[20987.396184] ieee80211 phy1: rt2x00lib_request_firmware: Info - 
Firmware detected - version: 0.29
[20987.851414] IPv6: ADDRCONF(NETDEV_UP): wlp0s18f2u4: link is not ready
[20989.368562] wlp0s18f2u4: authenticate with 74:25:8a:3f:79:d1
[20989.425297] wlp0s18f2u4: send auth to 74:25:8a:3f:79:d1 (try 1/3)
[20989.434313] wlp0s18f2u4: authenticated
[20989.439817] wlp0s18f2u4: associate with 74:25:8a:3f:79:d1 (try 1/3)
[20989.444114] wlp0s18f2u4: RX AssocResp from 74:25:8a:3f:79:d1 
(capab=0x8421 status=0 aid=130)
[20989.450763] wlp0s18f2u4: associated
[20989.450812] IPv6: ADDRCONF(NETDEV_CHANGE): wlp0s18f2u4: link becomes 
ready
[21700.838273] ieee80211 phy1: rt2x00queue_flush_queue: Warning - Queue 
14 failed to flush
[21705.251761] IPv6: ADDRCONF(NETDEV_UP): wlp0s18f2u4: link is not ready
[21713.142829] wlp0s18f2u4: authenticate with 74:25:8a:3f:79:d1
[21713.199602] wlp0s18f2u4: send auth to 74:25:8a:3f:79:d1 (try 1/3)
[21713.201715] wlp0s18f2u4: authenticated
[21713.204008] wlp0s18f2u4: associate with 74:25:8a:3f:79:d1 (try 1/3)
[21713.210193] wlp0s18f2u4: RX AssocResp from 74:25:8a:3f:79:d1 
(capab=0x8421 status=0 aid=130)
[21713.218064] wlp0s18f2u4: associated
[21713.218114] IPv6: ADDRCONF(NETDEV_CHANGE): wlp0s18f2u4: link becomes 
ready
[21803.494111] INFO: NMI handler (perf_event_nmi_handler) took too long 
to run: 1.026 msecs

I hope someone here can help me find a solution to this incredibly 
annoying problem.


*With DHCP, I got disconnected from the wifi AP with 'journalctl' 
showing some errors about 'carrier lost'. With 'static IP', I don't get 
disconnected but can't access internet either.