Wifi network speed decreased after hibernation

[Carl Beech]

Normally (after cold boot / reboot), ping time to router is normally approx 1-2ms, after a hibernation, the wifi comes back up, however, the time starts at 100ms, and for each ping, decreases by 1ms until approx 3-4ms, then goes back to 100ms.

Except from LSHW:

                description: Wireless interface
                product: AR928X Wireless Network Adapter (PCI-Express)
                vendor: Atheros Communications Inc.
                physical id: 0
                bus info: pci@0000:06:00.0
                logical name: wmaster0
                version: 01
                serial: 00:22:43:1e:bd:80
                width: 64 bits
                clock: 33MHz
                capabilities: pm msi pciexpress msix bus_master cap_list logical ethernet physical wireless
                configuration: broadcast=yes driver=ath9k ip=192.168.104.141 latency=0 module=ath9k multicast=yes wireless=IEEE 802.11bgn

ProblemType: Bug
Architecture: i386
Date: Sun Jul 26 16:42:19 2009
DistroRelease: Ubuntu 9.10
HibernationDevice: RESUME=UUID=6a5a2cff-a207-48ab-9a72-1299b9a671a5
MachineType: ASUSTeK Computer Inc. F5GL
NonfreeKernelModules: nvidia
Package: linux-image-2.6.31-4-generic 2.6.31-4.22
ProcCmdLine: root=UUID=7e8eafeb-d9fc-4973-bf32-2beb54a0cdf4 ro quiet splash
ProcEnviron:
 LANGUAGE=
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-4.22-generic
RelatedPackageVersions: linux-backports-modules-2.6.31-4-generic N/A
SourcePackage: linux
Uname: Linux 2.6.31-4-generic i686
dmi.bios.date: 09/08/2008
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 207
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: F5GL
dmi.board.vendor: ASUSTeK Computer Inc.
dmi.board.version: 1.0
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer Inc.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr207:bd09/08/2008:svnASUSTeKComputerInc.:pnF5GL:pvr1.0:rvnASUSTeKComputerInc.:rnF5GL:rvr1.0:cvnASUSTeKComputerInc.:ct10:cvr:
dmi.product.name: F5GL
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK Computer Inc.

[Carl Beech (carl-beech)]

Additional information:

If I turn off Wifi (using the switch on the side of the laptop - i.e. hardware switch), before hibernation, then switch back on after the machine has been woken up, then the WiFi works correctly.

Thanks

Carl.

[Tom Kirby (tc-kirby)]

I get what looks like a very similar problem on Karmic. I've found a workaround that works at the moment is to unload and reload the wireless driver like this:

sudo modprobe -r ath9k
sudo modprobe ath9k

Obviously, save your work before you try it in case it crashes your computer.