I have read in many places that certain USB problems are mitigated by adding dwc_otg.speed=1 to the cmdline.txt (I added it after the first parm, which is also a dwc_otg setting). This is the only change I've made to cmdline.txt.
(The problems I am having relate to USB sound unit, but I'll save them for another question. My understanding, is that that problem can be helped by reducing the USB speed).
When I add dwc_otg.speed=1 to the cmdline.txt file, I end up with a broken USB.
- Tried on October 28 Wheezy
- Tried on Oct28 after doing a full upgrade yesterday
- Tried on Dec16 wheezy, basically 'out of the box' (installed mpg321 only)
I have a 'rev 2'. no overclocking
In each case the result is the same: Pi boots, appears fairly normal, lists some USB detection info, and goes to login prompt, but keyboard is dead. Not even lights. Mouse is dead (no light). Even if I boot cold with just the keyboard, no function.
The network is also non-functional since I can't ssh into the unit. There's actually an error message towards the end of the boot which probably relates to this, and sshd takes longer to start than usual.
So, what is the situation regarding this parameter? Is there some other change I need to make to cmdline.txt? For, me, after a fair bit of trying, I've seen no effect ever from this change, other than to make the whole USB non-functional, which is very puzzling since it's been discussed a fair bit on the forums.