USB :Insufficient available bus power
 

Hi all
I am working on TI's OMAP3530 board with Android Kernel.when i plug in the USB webcam i am getting " rejected 1 configuration due to insufficient available bus power".Can anyone kindly tell me how power negotiation happens between USB and processor?when does this "insufficient available bus power" occur?Is there any workaround for this?

Thanks & Regards
Suma

Not all sure about the software side, but isn't the solution as easy as using a separately powered USB hub?

Or a separate power supply for the device?

Do you already have a lot of other devices plugged into the USB bus on that machine?

A local cellphone conglomerate here, for example, offers a USB cell-modem that has two USB plugs - you only need one for it to actually work, but if you use both (thus drawing more power) it can use a high-speed data transfer mode.

Also, it could just be that that system you are developing on does not give full USB-spec power to the USB bus - which might be getting more common as modern boards try to be more energy-friendly. Are you sure the bus is "awake" (i. e. there is not some sort of power limiting setting in the BIOS) that tries to conserve power if the bus is not in use? Maybe you need to pull a line down (or up) somewhere on the bus to "wake it up" (go to full power) before you try to access the cam?? (Probably first trigger a bus interrupt in software?)