On 18/01/17, Greg KH wrote:
On Wed, Jan 18, 2017 at 05:05:34PM +0100, Oliver Graute wrote:
Hello list,
i'am using a GSM/UMTS Module on a PCB which is connected with USB 2.0 Hi-Speed to my imx6ul CPU. To reduce our Electromagnetic compatibility and to make my hardware colleges happy again I want to downgrade to USB Full Speed.
How can I tell the Linux Kernel to Do so?
You can't. It's up to the device to tell the host what "speed" it is running at. See the USB spec for all of the crazy details.
ok thx for this important hint
I suggest you modify the firmware of your modem to do this, that's the only way it is going to work (note, your device needs to be able to support full speed, it might not be able to do that.)
I know that the cinterion gsm module support full speed. I have to check their docs how to force the module into fullspeed. Best Regards, Oliver