On Sat, 8 Sep 2012, Greg KH wrote: > On Sat, Sep 08, 2012 at 02:06:19PM -0400, Florian W� wrote: > > > > Hello everybody, > > > > I am trying to get a USB IO Board running with Debian on Raspberry > > PI and other 2.6.+ distributions (e.g. Ubuntu 12.04). > > > > The board used to run fine with kernel 2.4.+ (e.g. Ubuntu 10.04) - a > > Device /dev/ttyACM0 was created and usable. > > But with newer kernels no device is created and dmesg tells: > > > > # dmesg > > [ 3.391258] usb 1-1.2: new full-speed USB device number 4 using dwc_otg > > [ 8.531474] usb 1-1.2: unable to read config index 0 > > descriptor/start: -32 > > [ 8.531510] usb 1-1.2: chopping to 0 config(s) > > [ 8.532305] usb 1-1.2: string descriptor 0 read error: -32 > > [ 8.532341] usb 1-1.2: New USB device found, idVendor=04d8, > > idProduct=000a > > [ 8.532359] usb 1-1.2: New USB device strings: Mfr=1, Product=2, > > SerialNumber=0 > > [ 8.532880] usb 1-1.2: no configuration chosen from 0 choices > > [ 8.532896] usb 1-1.2: No support over 500mA > > You are sucking too much power for the device, try plugging a powered > hub in and the device into that, and then all should be good. That line in the log is misleading. (In fact, I don't know where it came from -- it doesn't seem to be present in the current kernel.) The power consumption is part of the configuration descriptors, and the log shows that the computer was not able to read any of the configs. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
