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USB Bug

Added by Benedikt K. almost 6 years ago

Hej hej,

we have noticed a usb bug on the MityDSP and we are not sure why this happens.

We are using linux 3.7.0+-kernel with our own baseboard. The socket is configured and initialized as USB_HOST (with mityomapl138_usb_init(MUSB_HOST);).

If I plug in a usb stick to the USB 2.0 socket, the device is recognized and mounted. If I then unplug the stick and plug in again or plug in another usb device, nothing is detected. I need a reboot to use the usb socket again.

If I use a usb hub on the MityDSP connector, it is recognized and I can plug and unplug several usb devices as often as I want. They are always detected and automounted. If I disconnect the usb hub from the MityDSP and plug it in again or plug in another device directly to the MityDSP, then again nothing is detected.

I suspect the usb driver has problem with suspending. Configuring the device from "auto" to "on" in /sys/bus/usb/devices/usb2/power/control does not change the behaviour. The runtime_status returns always "active".

I compiled the kernel with and without the CONFIG_USB_SUSPEND and the CONFIG_USB_OTG option, but this doesn't change anything.

Do you have any idea what might cause this problem?

Best regards, Benedikt


Replies (5)

RE: USB Bug - Added by Benedikt K. almost 6 years ago

Another thing: When I plug in the first usb device the number of usb interrupts in /proc/interrupts increases. When I unplug it, it stops as expected. But not a single interrupt happens when I plug in another device after unplugging the first one.

RE: USB Bug - Added by Michael Williamson almost 6 years ago

Hello,

Are you using a 3.7 branch from our git site, or the mainline? I don't think we officially support 3.7. Do you see the same behaviour in 3.2?

-Mike

RE: USB Bug - Added by Benedikt K. almost 6 years ago

It is from your git page - as far as I remember. Our software student tried to jump to 3.14 two month ago but it didn't work completly so we jumped only to 3.7. as this seemed to work.

RE: USB Bug - Added by Jonathan Cormier almost 6 years ago

Note that we have seen a similar issue on the 335x. Could you checkout the following page and report back if the solution helps?

https://support.criticallink.com/redmine/projects/armc8-platforms/wiki/Using_USB_port

RE: USB Bug - Added by Jonathan Cormier almost 6 years ago

There are several missing features in the 3.14 branch that I found when trying to move to it. I created a tag to mark my findings.
http://support.criticallink.com/gitweb/?p=linux-davinci.git;a=tag;h=refs/tags/3.14_Note

I'm not sure of the state of the 3.7 kernel other than it boots and usb appeared to be working.

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