• Registered: 2012-01-04
  • Posts: 7

Topic: WIFI wlan0: link not ready [ROBOT MODE]

I am new to the 3.5" Infocast, as I just got it for Christmas.   I am trying to learn something about embedded Linux by hacking around on this device.  I found the Chumby article that describes putting the device into robot mode.

http://www.linuxtoys.org/chumbot/chumby_as_robot.pdf

I followed all the steps, and it mostly worked.  My problem is that I do not get a WIFI connection for most of the boots when in robot mode.   If I revert to the flash mode, then it seems to always find an IP address.  When in robot mode, it will not get an IP address on 9 of 10 boots. 

I attached a serial port and watched the boot process.  On the failed boots, it gets a message:

[   18.410000] ADDRCONF(NETDEV_UP): wlan0: link is not ready

And then immediately continues on and completes some script.   I am at a console prompt, but the wlan0  Access Point: Not-Associated.   When it works,  there appears to be a pause after the first "link is not ready" and it then finds a link and wlan0 Access Point appears to contain a MAC address. 

When I am in the bad state, nothing I could come up with from the console prompt will fix the WIFI.  I tried ifconfig to turn the link off and on.   I tried calling iwconfig with the parameters again.   I tried to invoke udhcpc, but I must not know the proper parameters, as it  just complains the device is invalid.

Questions:

1.  Can someone point me to the scripts that are running when in robot mode?  What different scripts are run in flash mode?   Or more generic, what scripts are run during the boot process?

2.  Is there some other sequence of network commands that I need to enter to fix the link?

3.  Any idea why the script pauses sometimes and waits for the link to be ready and other times it just quickly continues on?

Thanks.

  • Registered: 2012-01-04
  • Posts: 7

Re: WIFI wlan0: link not ready [ROBOT MODE]

FYI,

I emailed Bob Smith, the author of the article quoted above.  He quickly responded with a suggestion that vastly improved my WIFI link rate.    Testing today, I got seven fails out of twelve boots.  After applying Bob's hint, I got only two fails out of twelve boots.

The script file is in /mnt/storage/bin.  The name of the script file is rcS.robot.    In the script file, I looked for the line

ifconfig lo 127.0.0.1 &

and after that line, Bob suggested adding the line

sleep 10

From what Bob told me, this sleep for 10 seconds will help some WIFI dongles recover from the USB reset that was done earlier in the script.  Since I have only the one Infocast right now, perhaps this problem is limited to only my unit.  However, if other see a similar issue, you may want to add this time delay.