Wifi dongle not working at boot time

[buitre-buitaker]

WiFi dongle works perfect with and without an usb hub, except at boot time.

If I boot with USB wifi dongle connected directly to the EV3 brick, it works and connect to wifi nicely.

If I boot with the USB wifi dongle connected to the USB hub and the hub connected to the EV3 brick, doesn't works. If I reconnect the USB wifi dongle to the hub once booted, the EV3 brick detect the device and connect to the wifi network.

It looks like the modules loading order for the hub and the wifi dongle is wrong. How can I change the loading order of the modules?

Thank you for your help

Antonio

[buitre-buitaker]

OK, I have more clues.

It looks like the hub is detected but when the wifi dongle is detected a EMI error arises.

DMESG returns this on boot:

[    3.775069] usb 1-1: New USB device found, idVendor=14cd, idProduct=8601
[    3.785641] usb 1-1: New USB device strings: Mfr=1, Product=3, SerialNumber=0
[    3.801691] usb 1-1: Product: USB 2.0 Hub
[    3.804225] usb 1-1: Manufacturer: USB Device
[    3.831856] hub 1-1:1.0: USB hub found
[    3.840200] hub 1-1:1.0: 4 ports detected
[    4.190024] usb 1-1.2: new full-speed USB device number 3 using ohci-da8xx
[    4.222187] usb usb1-port1: disabled by hub (EMI?), re-enabling...
[    4.226866] usb 1-1: USB disconnect, device number 2
[    4.230151] usb 1-1-port2: attempt power cycle
[    5.000032] usb 1-1: new low-speed USB device number 7 using ohci-da8xx
[    5.220019] usb 1-1: device descriptor read/64, error -62
[    5.560007] usb 1-1: device descriptor read/64, error -62
[    5.899957] usb 1-1: new low-speed USB device number 8 using ohci-da8xx
[    6.130000] usb 1-1: device descriptor read/64, error -62
[    6.470000] usb 1-1: device descriptor read/64, error -62
[    6.600294] usb usb1-port1: attempt power cycle
[    7.150007] usb 1-1: new low-speed USB device number 9 using ohci-da8xx
[    7.609975] usb 1-1: device not accepting address 9, error -62
[    7.829996] usb 1-1: new low-speed USB device number 10 using ohci-da8xx
[    8.290004] usb 1-1: device not accepting address 10, error -62
[    8.311195] usb usb1-port1: unable to enumerate USB device

[buitre-buitaker]

OK, more in depth, it looks like a hardware issue.

I am looking for a usb hub and wifi dongle setup quite compact, smallest sizes and short cables.

I looks like I need some kind of EMI decoupling between the hub and the wifi dongle.

I f I put a usb cable between the usb hub and the wifi dongle, it works without any problem.

Perhaps is it a question for other forum, but: anyone has this problem? any compact solution for decoupling wifi dongle from the usb hub?

Thank you