Kernel Panic When Trying to Use USB Wifi

Started by hngjms, May 17, 2016, 01:35:04 AM

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hngjms

I have an rtl8192cu usb wifi dongle (think it's this one http://www.amazon.com/Edimax-EW-7811Un-150Mbps-Raspberry-Supports/dp/B003MTTJOY).

When I try to use it on my A20 SOM EVB board it kernel panics and then restarts.
I'm running on the "A20-SOM Debian Jessie with kernel 3.4.103+ release 6, for boards revisions C and D"
found here: https://www.olimex.com/Products/SOM/A20/A20-SOM/

this is my /etc/network/interfaces

iface wlan0 inet dhcp
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp


this is my /etc/wpa_supplicant/wpa_supplicant.conf

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
ssid="routername"
psk="pswd"
}


here is my uart output. It's a bit long so I stuck it in a pastebin.
http://pastebin.com/fbUW7axF


JohnS

Start by checking power used / needed & provided.

John

soenke

Does it reboot as soon as you plug in the dongle or when it does a DHCP request? Or later?

hngjms

#3
Quote from: JohnS on May 18, 2016, 12:59:59 PM
Start by checking power used / needed & provided.

I'm using a 9V 1.4A power supply for the board, and I've tried plugging in my USB Wifi dongle straight into the board as well as into
a usb hub with it's own power supply.

Quote from: soenke on May 20, 2016, 12:10:16 PM
Does it reboot as soon as you plug in the dongle or when it does a DHCP request? Or later?

It reboots on DHCP request (when I do an ifup wlan0). On plug in the driver/firmware seem to load normally.

Oh, I also accidentally started with an A10 Lime board image. I think the mali GPU drivers didn't work properly because video was super laggy but the wifi dongle didn't cause kernel panic on that one. On the A20 image the video is better but I'm stuck on ethernet. 


soenke

Maybe i am wrong, but dont you need 5V instead of 9V?

Does the hangup also happen when doing the same on eth0?

JohnS

Looks like 5V only.

Unless there's something he's failed to post?

John

hngjms

#6
Sorry guys I didn't realize there was a stand alone A20-SOM board with different power requirements. I have the A20-SOM-EVB rated for "6V to 16V DC voltage".   :D

hngjms

Quote from: soenke on May 21, 2016, 12:38:08 AM
Maybe i am wrong, but dont you need 5V instead of 9V?

Does the hangup also happen when doing the same on eth0?

Ethernet works fine.

soenke

Still, 1.4A might be not enough. Please try another power source just to rule that out.

If the A10 image has the same kernel version, check if you can copy the wlan modules to the A20 image, maybe there was something wrong with the kernel config.

Furthermore you can try to use one of igors kernel images, he also prepared a mainline version.