What i can see in my cmdline.txt there are some misspelling.
And have you tested to passed the parameter to the usb device to say that just doing usb 1.1.
Added the dwc_otg.speed=1 parameter to force USB to work only in full speed mode (speed of USB 1.1).
What i can se in my cmdline.txt there are picore 7.0.
c_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=/dev/ram0 elevator=d
eadline rootwait quiet nortc loglevel=3 noembed
There sould be dwc_otg.lpm_enable...not just c_otg.
Just google of this parameters, get lots of performance/hanging problems with usb devices with raspberry pi.
Take a look at all this parameters
cd /sys/module/dwc_otg/parameters
ls
for i in $(ls);do echo $i----$(cat $i);done