AnsweredAssumed Answered

imx6 usb throws "Device or resource busy"

Question asked by c xh on Apr 2, 2014

Hi,

 

We're usb printer "GPrinter" on imx6 device. It's OK now for first plugin.

But if we plug out the plugin the device again, it will throw "Device or resource busy" when access the device.

Any suggestion about this problem? Thank you!

 

Software version:

android 4.04

linux 3.0.35

 

Test steps:

1. Configure and build linux usb printer as a module.

   After building, we can get the module files

     kernel_imx/drivers/usb/class/usblp.ko

 

2. Insert the module on imx6

    insmod usblp.ko

 

3. Plugin the USB printer.

    After plugin the printer, we found the driver was successfully install, and then we create the device file manually

      busybox mknod /dev/printer c 180 0

 

4. Output text to printer, It's OK!

      echo "text" > /dev/printer

 

5. Plug out the usb printer, and plug in again.

   After that we found the USB device was successfully enumerated.

   But if we try to output text to the printer device

      echo "text" > /dev/printer

  It gives error "Device or resource busy".

 

BTW, we tested the printer on both PC linux and AllWinner android,

and found no problem after plug out and plug in the device.

Outcomes