I have writed a usb video driver.And the video device which change its display every 1second display the current time.
And I test the driver in PC.It works OK.Every 1 second,The display is changed to the next second.
But when running it in ARM Board,The time of changing diaplay is not stablity.Sometimes after 0.7 second ,the display is changed to the next second.Sometimes after 1.9 second,the display is changed to the next second.
In PC the usb video device work on EHCI(High Speed)
IN ARM the usb video device work on EHCI(Full Speed)
On Full Speed,the usb video device cannot work OK?or because of other things?
How to change Full Speed to High Speed?