Low resolution when using usb camera

hi,

I connect an usb camera to the board (mini2440),but I can only get image of
 320x240. I use V4L2 for programming.

Does anyone know how achieve higher resolution ?

The same camera can capture image of 640x480 when connected to a Win xp
machine.

tks a lot.

Does this camera require a high speed connection to be able to provide
640/480? The Mini2440 is only capable up to full speed.