• Resolved

USB issues

Hi I recently bought a Beaglebone, I am student  learning about embedded electronics and i figured the beaglebone would be a great place to start. it was small, has ethernet and usb on board on top of a ton of IO. Well seeing how i had some usb devices I figured i could put together something really cool with my usb bluetooth dongle and usb camera. I first connected my camera and started to see if i can capture data from it, to my disappointment i could not I was getting select timeout errors from the video camera interface module. So after googling I found out there is a bug in the usb stack that seemed like data intensive devices might be an issue with kernel. So  i decided to try my bluetooth dongle thinking i could come up with a simple project for it. Unfortunately a similar thing happened trying to bring the bluetooth interface up i get a read time error. As a young student and someone starting off in embedded development this really leaves a sour taste in my mouth that makes me not want to work with any TI products. If you are working on a fix for this let the community know about it and not leave us in the dark. 

Christopher Campbell

  • Genius 9460 points


    Would suggest to use latest kernel tree below which has usb driver updated. This should make camera working.


    On bluetooth, would you try below;

    1) Disable USB DMA at drivers->USB support->Inventra-> select [*] Disable DMA  and see if this solves the issue which would confirm the issue to be due to DMA otherwise there may be some setup issue.


    If my reply answers your question then please click on the green button "Verify Answer"

  • In reply to Ajay:

    This indeed fixed my problem both with the webcam and the Bluetooth module. Though since this is a known issue with the usb stack I would assume the DMA would be disabled from the start, at least until there is a reliable fix available. 

    Thank you just the same A.J

  • In reply to Ajay:

    In the a roadmap to fix USB DMA issues for the upcoming release of AM335x-PSP? We are users of BeagleBone (Rev. A5 mostly) and we are also facing problems when we use more than 3 3G USB modems connected to D-Link USB hub. Symptoms that we are facing is unability to establish a PDP context, ~50% packet loss, "busy" messages in dmesg from musb driver and similar. CONFIG_MUSB_PIO_ONLY=Y and CONFIG_PREEMPT=Y and it does solve the problem for only some time after reboot.

    There are also other threads related to this issue: