wlan0 failing when running on battery


I have a Toshiba a505-s6986 laptop with a realtek 8191se wireless chip. The wireless works flawlessly on AC but will drop the connection several times before failing all together when running on battery. It “seems” that the lower the battery level the worse the problem becomes. However, it starts failing well above 50%.

I am dual boot with Win7 and if I reboot into windows the wireless works fine right up to the point the battery goes critical and shuts down the pc.

So, I assume it is an issue with the realtek linux driver. Is there some kind of power management that is not setup correctly? It is irritating when trying to use the laptop on battery power.

I hope someone has some insight into this.

Appreciate it!

Check the output from;

iwconfig wlan0 |grep Management

If on battery it’s on, you can turn it off via

sudo iwconfig wlan0 power off

Cheers Malcolm °¿° (Linux Counter #276890)
SUSE Linux Enterprise Desktop 11 (x86_64) Kernel
up 2 days 13:48, 2 users, load average: 0.02, 0.06, 0.08
GPU GeForce 8600 GTS Silent - CUDA Driver Version: 190.18

If you were to compare the RealTek vendor driver with any mainline driver, you
would be surprised that it works at all, not that it fails in some situations.

That driver is in staging, which is where sub-standard drivers are placed. They
are guaranteed to compile, but nothing else is ensured.

Thanks for the replies guys.

The output of iwconfig wlan0 | grep Management when on battery is:

Power Management period:0us mode:All packets received

If I run iwconfig wlan0 power off and check Management again it still says period 0us etc. It does not seem to shut off. But the darn connection sure does.

When I am on AC power, the power management says that it is off for wlan0. So it is definitely going into power saving mode.

I notice there are some errors in the boot log related to cant parse some lines from the wireless script - I need to look into that.

You mentioned mainline driver as opposed to Realtek driver. Is there another (better) driver for this device?

Thanks again.

On 01/18/2010 08:56 PM, etch wrote:
> You mentioned mainline driver as opposed to Realtek driver. Is there
> another (better) driver for this device?

No. The Realtek driver is the one in staging in mainline.

Just looking through old posts. Since I posted this there have been 2 updates to the realtek driver. 8192se I think it is ( not at my laptop ). Anyway, the problem has been fixed and now works well when on battery.

Just in case its of use to anyone else.