blog.crox.net (Entries tagged as wlan)

Disable WiFi Power Management on Raspbian 12 (Network Manager)

nospam@example.com (crox) — Fri, 15 Aug 2025 22:48:00 +0000

8 years later there are still issues on Raspberry Pi / Raspbian with WiFi power management causing disconnects and generally bad performance.

I've found a reliable method to disable WiFi Power Management for the on-board WiFi chip (brcmfmac) here: NetworkManager WiFi Power Saving.

How to solve Edimax EW-7612UAn v2 (7392:7822) power management issues on Raspberry Pi (Raspbian WiFi disconnect)

nospam@example.com (crox) — Sun, 12 Nov 2017 19:04:00 +0000

On Raspbian, you don't need to install the 8192cu driver manually, as it comes with the distribution

To avoid disconnection issues, you need however to disable power management. This needs to be done in two places. First, this is what I have in /etc/modprobe.d/8192cu.conf:
```
options 8192cu rtw_power_mgnt=0 rtw_enusbss=0
```

This alone did not prevent the issue. I also had to add this entry to /etc/network/interfaces:

auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
wireless-power off
iface default inet dhcp

Sources: https://github.com/xbianonpi/xbian/issues/217, https://www.kuerbis.org/2016/03/raspberry-pi-3-kurztipps-wlan-sleep-mode-verhindern/

Recovering an unmanageable WRT54GL (OpenWRT lost password)

nospam@example.com (crox) — Fri, 19 Jun 2009 18:53:30 +0000

A friend recently brought us a Linksys WRT54GL which had been laying around for a while and whose password was not available anymore.

None of the "easy" password recovery methods seemed to work (like holding the reset button, power-cycling etc.) - possibly because the corresponding options had been previously disabled.

In the end, I used the TFTP method described here: http://oldwiki.openwrt.org/OpenWrtDocs(2f)Installing(2f)TFTP.html

However, it didn't work until all these conditions were met:

- the laptop with the firmware image and the tftp client had to be connected to the WRT through an external switch

- the switch had to be unplugged from the LAN

- I had to lauch a "ping -f 192.168.1.1" in a different terminal before powering on the WRT in order for the tftp transfer to start

- before and after the flashing I followed the 30/30/30 procedure (not sure if that one is mandatory but it is recommended)

To make sure the hardware was working I installed the latest firmware from the Linksys website (WRT54GL_v4.30.11_012_ETSI_EN_code.bin), but now I'll likely reflash it with OpenWRT - this time from the web interface :o)

Linksys WAG200G-EU stops routing UDP after a while (scripted reboot how-to)

nospam@example.com (crox) — Fri, 07 Mar 2008 10:04:25 +0000

It seems that after having been up for a couple of days, the WAG200G starts having issues routing UDP packets properly. This particularly affects VoIP traffic (here IAX2 on port 4569). The symptoms are that "regular surfing" works flawlessly, but the registration with the asterisk server fails. tcpdump shows no traffic on the server side. Restarting the WAG200G immediately solves the problem.

Here is how I restarted the router from the command line:

wget --http-user=admin --http-password=pa55w0rd \
     --post-data='reboot=1&save=Enregistrer+les+param%E8tres&todo=reboot&h_reboot=1&this_file=Reboot.htm&next_file=index.htm&message=' \
     http://192.168.0.1/setup.cgi

(replace password and IP address as appropriate)