Device connected to USB port is not detected


#1

Hello,

I connected the board to my desktop through USB (J4). Ubuntu is running in my desktop. After connecting, I checked for ‘lsusb’ and it does not list the board.

Am I missing something?

Thanks


#2

I connected the board to my desktop through USB (J4). Ubuntu is running in my desktop. After connecting, I checked for ‘lsusb’ and it does not list the board.

Am I missing something?

Depends what you expect it to do.

J4 is mostly for programming the board; and to put it into programming
mode you need to hold down certain keys during power on. I think it
is possible to run it as a USB gadget whilst Debian is running but you
would have to configure this yourself. It won’t do that out of the box.


#3

Did you press and hold (for a while) the (-) S4 button while powering-up the board?
I suppose you’re trying to re-flash the board via “fastboot method”.


#5

Hi all,

I’m looking at using the db820c as a usb gadget/peripheral too.

in theory this can be tested using a modprobe g_ether/g_serial/g_audio …

That’s for sure feasible since aboot is using it for this purpose.

There is patches that have been posted on linux-arm-msm by codeaurora folks.
It seems dts change are required as well as a new dwc3-qcom driver for vbus detection.
Some usb phy related patch may be required too.

After Applying all these patch, usb peripheral mode is still failing so I may miss something.

If @vgautam is around maybe he can help to find a git test branch to enable the usb2 as a peripheral mode, on top of the linaro 4.14 release.

Regards,
Julien


#6

Hi Julien: You should be able to use the micro USB port on the 820c as a USB gadget. I did something similar with the 410c board so that I could run it headless (no display). My instructions are at developer.qualcomm.com/MLH although these instructions were for the 410c board, they should work for the 820c board.

Full disclosure: I am currently unemployed and looking for work.


#7

Hi Ijking,

Yes basically it should be as simple thant pluging the micro usb cable to my usb host computer,
and running modprobe g_ether on the target.

But the usb support of the DB820c is not ready for peripheral support.

what I see from my computer is that the target doesn’t enumerate


kernel: usb 1-1.4: new high-speed USB device number 5 using ehci-pci

kernel: usb 1-1.4: device descriptor read/64, error -110
kernel: usb 1-1.4: device descriptor read/64, error -71

kernel: usb 1-1.4: device not accepting address 8, error -71
kernel: usb 1-1-port4: unable to enumerate USB device

When looking at dwc3 ‘gadget.c’ driver I noticed that the IRQ callback is
never raised (dwc3_interrupt, dwc3_thread_interrupt)

So there is something missing in 4.14 linaro kernel to make it works.
Either dwc3 patch, usb-phy, dts, regulator ?

Julien